Approaching Zero Part 1

Approaching Zero.

by Paul Mungo.

PROLOGUE.

Fry Guy watched the computer screen as the cursor blinked. Beside him a small electronic box chattered through a call routine, the numbers clicking audibly as each of the eleven digits of the phone number was dialed. Then the box made a shrill, electronic whistle, which meant that the call had gone through; Fry Guy's computer had been connected to another system hundreds of miles away.

The cursor blinked again, and the screen suddenly changed. WELCOME TO CREDIT SYSTEMS OF AMERICA, it read, and below that, the cursor pulsed beside the prompt: ENTER ACCOUNT NUMBER.

Fry Guy smiled. He had just broken into one of the most secure computer systems in the United States, one which held the credit histories of millions of American citizens. And it had really been relatively simple. Two hours ago he had called an electronics store in Elmwood, Indiana, which--like thousands of other shops across the country--relied on Credit Systems of America to check its customers' credit cards.

"Hi, this is Joe Boyle from CSA ... Credit Systems of America," he had said, dropping his voice two octaves to sound older--a lot older, he hoped--than his fifteen years. He also modulated his natural midwestern drawl, giving his voice an eastern tw.a.n.g: more big-city, more urgent.

"I need to speak to your credit manager ... uh, what's the name? Yeah, Tom. Can you put me through?"

Tom answered.

"Tom, this is Joe Boyle from CSA. You've been having some trouble with your account?"

Tom hadn't heard of any trouble.

"No? That's really odd.... Look, I've got this report that says you've been having problems. Maybe there's a mistake somewhere down the line. Better give me your account number again."

And Tom did, obligingly reeling off the eight-character code that allowed his company to access the CSA files and confirm customer credit references. As Fry Guy continued his charade, running through a phony checklist, Tom, ever helpful, also supplied his store's confidential CSA pa.s.sword. Then Fry Guy keyed in the information on his home computer. "I don't know what's going on," he finally told Tom. "I'll check around and call you back."

But of course he never would. Fry Guy had all the information he needed: the account number and the pa.s.sword. They were the keys that would unlock the CSA computer for him. And if Tom ever phoned CSA and asked for Joe Boyle, he would find that no one at the credit bureau had ever heard of him. Joe Boyle was simply a name that Fry Guy had made up.

Fry Guy had discovered that by sounding authoritative and demonstrating his knowledge of computer systems, most of the time people believed he was who he said he was. And they gave him the information he asked for, everything from account codes and pa.s.swords to unlisted phone numbers. That was how he got the number for CSA; he just called the local telephone company's operations section.

"Hi, this is Bob Johnson, Indiana Bell tech support," he had said. "Listen, I need you to pull a file for me. Can you bring it up on your screen?"

The woman on the other end of the phone sounded uncertain. Fry Guy forged ahead, coaxing her through the routine: "Right, on your keyboard, type in K--P pulse.... Got that? Okay, now do one-two-one start, no M--A.... Okay? "Yeah? Can you read me the file? I need the number there...."

It was simply a matter of confidence--and knowing the jargon. The directions he had given her controlled access to unlisted numbers, and because he knew the routine, she had read him the CSA number, a number that is confidential, or at least not generally available to fifteen-year-old kids like himself.

But on the phone Fry Guy found that he could be anyone he wanted to be: a CSA employee or a telephone engineer--merely by pretending to be an expert. He had also taught himself to exploit the psychology of the person on the other end of the line. If they seemed confident, he would appeal to their magnanimity: "I wonder if you can help me ..." If they appeared pa.s.sive, or unsure, he would be demanding: "Look, I haven't got all day to wait around. I need that number now." And if they didn't give him what he wanted, he could always hang up and try again.

Of course, you had to know a lot about the phone system to convince an Indiana Bell employee that you were an engineer. But exploring the telecommunications networks was Fry Guy's hobby: he knew a lot about the phone system.

Now he would put this knowledge to good use. From his little home computer he had dialed up CSA, the call going from his computer to the electronic box beside it, snaking through a cable to his telephone, and then pa.s.sing through the phone lines to the unlisted number, which happened to be in Delaware.

The electronic box converted Fry Guy's own computer commands to signals that could be transmitted over the phone, while in Delaware, the CSA's computer converted those pulses back into computer commands. In essence, Fry Guy's home computer was talking to its big brother across the continent, and Fry Guy would be able to make it do whatever he wanted.

But first he needed to get inside. He typed in the account number Tom had given him earlier, pressed Return, and typed in the pa.s.sword. There was a momentary pause, then the screen filled with the CSA logo, followed by the directory of services--the "menu."

Fry Guy was completely on his own now, although he had a good idea of what he was doing. He was going to delve deeply into the accounts section of the system, to the sector where CSA stored confidential information on individuals: their names, addresses, credit histories, bank loans, credit card numbers, and so on. But it was the credit card numbers that he really wanted. Fry Guy was short of cash, and like hundreds of other computer wizards, he had discovered how to pull off a high-tech robbery.

When Fry Guy was thirteen, in 1987, his parents had presented him with his first computer--a Commodore 64, one of the new, smaller machines designed for personal use. Fry Guy linked up the keyboard-sized system to an old television, which served as his video monitor.

On its own the Commodore didn't do much: it could play games or run short programs, but not a lot more. Even so, the machine fascinated him so much that he began to spend more and more time with it. Every day after school, he would hurry home to spend the rest of the evening and most of the night learning as much as possible about his new electronic plaything.

He didn't feel that he was missing out on anything. School bored him, and whenever he could get away with it, he skipped cla.s.ses to spend more time working on the computer. He was a loner by nature; he had a lot of acquaintances at school, but no real friends, and while his peers were mostly into sports, he wasn't. He was tall and gawky and, at 140 pounds, not in the right shape to be much of an athlete. Instead he stayed at home.

About a year after he got the Commodore, he realized that he could link his computer to a larger world. With the aid of an electronic box, called a modem, and his own phone line, he could travel far beyond his home, school, and family.

He soon upgraded his system by selling off his unwanted possessions and bought a better computer, a color monitor, and various other external devices such as a printer and the electronic box that would give his computer access to the wider world. He installed three telephone lines: one linked to the computer for data transmission, one for voice, and one that could be used for either.

Eventually he stumbled across the access number to an electronic message center called Atlantic Alliance, which was run by computer hackers. It provided him with the basic information on hacking; the rest he learned from telecommunications manuals.

Often he would work on the computer for hours on end, sometimes sitting up all night hunched over the keyboard. His room was a sixties time warp filled with psychedelic posters, strobes, black lights, lava lamps, those gift-shop relics with blobs of wax floating in oil, and a collection of science fiction books. But his computer terminal transported him to a completely different world that encompa.s.sed the whole nation and girdled the globe. With the electronic box and a phone line he could cover enormous distances, jumping through an endless array of communications links and telephone exchanges, dropping down into other computer systems almost anywhere on earth. Occasionally he accessed Altos, a business computer in Munich, Germany owned by a company that was tolerant of hackers. Inevitably, it became an international message center for computer freaks.

Hackers often use large systems like these to exchange information and have electronic chats with one another, but it is against hacker code to use one's real name. Instead, they use "handles," nicknames like The Tweaker, Doc Cypher and Knightmare. Fry Guy's handle came from a commercial for McDonald's that said "We are the fry guys."

Most of the other computer hackers he met were loners like he was, but some of them worked in gangs, such as the Legion of Doom, a U.S. group, or Chaos in Germany. Fry Guy didn't join a gang, because he preferred working in solitude. Besides, if he started blabbing to other hackers, he could get busted.

Fry Guy liked to explore the phone system. Phones were more than just a means to make a call: Indiana Bell led to an immense network of exchanges and connections, to phones, to other computers, and to an international array of interconnected phone systems and data transmission links. It was an electronic highway network that was unbelievably vast.

He learned how to dial into the nearest telephone exchange on his little Commodore and hack into the switch, the computer that controls all the phones in the area. He discovered that each phone is represented by a long code, the LEN (Line Equipment Number), which a.s.signs functions and services to the phone, such as the chosen long-distance carrier, call forwarding, and so on. He knew how to manipulate the code to reroute calls, rea.s.sign numbers, and do dozens of other tricks, but best of all, he could manipulate the code so that all his calls would be free.

After a while Indiana Bell began to seem tame. It was a convenient launching pad, but technologically speaking it was a wasteland. So he moved on to BellSouth in Atlanta, which had all of the latest communications technology. There he became so familiar with the system that the other hackers recognized it as his SoI--sphere of influence--just as a New York hacker called Phiber Optik became the king of NYNEX (the New York-New England telephone system), and another hacker called Control C claimed the Michigan network. It didn't mean that BellSouth was his alone, only that the other members of the computer underworld identified him as its best hacker.

At the age of fifteen he started using chemicals as a way of staying awake. Working at his computer terminal up to twenty hours a day, sleeping only two or three hours a night, and sometimes not at all, the chemicals--uppers, speed-- kept him alert, punching away at his keyboard, exploring his new world.

But outside this private world, life was getting more confusing. Problems with school and family were beginning to acc.u.mulate, and out of pure frustration, he thought of a plan to make some money.

In 1989 Fry Guy gathered all of the elements for his first hack of CSA. He had spent two years exploring computer systems and the phone company, and each new trick he learned added one more layer to his knowledge. He had become familiar with important computer operating systems, and he knew how the phone company worked. Since his plan involved hacking into CSA and then the phone system, it was essential to be expert in both.

The hack of CSA took longer than he thought it would. The account number and pa.s.sword he extracted from Tom only got him through the credit bureau's front door. But the codes gave him legitimacy; to CSA he looked like any one of thousands of subscribers. Still, he needed to get into the sector that listed individuals and their accounts--he couldn't just type in a person's name, like a real CSA subscriber; he would have to go into the sector through the back door, as CSA itself would do when it needed to update its own files.

Fry Guy had spent countless hours doing just this sort of thing: every time he accessed a new computer, wherever it was, he had to learn his way around, to make the machine yield privileges ordinarily reserved for the company that owned it. He was proficient at following the menus to new sectors and breaking through the security barriers that were placed in his way. This system would yield like all the others.

It took most of the afternoon, but by the end of the day he, chanced on an area restricted to CSA staff that led the way to the account sector. He scrolled through name after name, reading personal credit histories, looking for an Indiana resident with a valid credit card.

He settled on a Visa card belonging to a Michael B. from Indianapolis; he took down his full name, account and telephone number. Exiting from the account sector, he accessed the main menu again. Now he had a name: he typed in Michael B. for a standard credit check.

Michael B., Fry Guy was pleased to see, was a financially responsible individual with a solid credit line.

Next came the easy part. Disengaging from CSA, Fry Guy directed his attention to the phone company. Hacking into a local switch in Indianapolis, he located the line equipment number for Michael B. and rerouted his incoming calls to a phone booth in Paducah, Kentucky, about 250 miles from Elmwood. Then he manipulated the phone booth's setup to make it look like a residential number, and finally rerouted the calls to the phone box to one of the three numbers on his desk. That was a bit of extra security: if anything was ever traced, he wanted the authorities to think that the whole operation had been run from Paducah.

And that itself was a private joke. Fry Guy had picked Paducah precisely because it was not the sort of town that would be home to many hackers: technology in Paducah, he snickered, was still in the Stone Age.

Now he had to move quickly. He had rerouted all of Michael B.'s incoming calls to his own phone, but didn't want to have to deal with his personal messages. He called Western Union and instructed the company to wire $687 to its office in Paducah, to be picked up by--and here he gave the alias of a friend who happened to live there. The transfer would be charged to a certain Visa card belonging to Michael B.

Then he waited. A minute or so later Western Union called Michael B.'s number to confirm the transaction. But the call had been intercepted by the reprogrammed switch, rerouted to Paducah, and from there to a phone on Fry Guy's desk.

Fry Guy answered, his voice deeper and, he hoped, the sort that would belong to a man with a decent credit line. Yes, he was Michael B., and yes, he could confirm the transaction. But seconds later, he went back into the switches and quickly reprogrammed them. The pay phone in Paducah became a pay phone again, and Michael B., though he was unaware that anything had ever been amiss, could once again receive incoming calls. The whole transaction had taken less than ten minutes.

The next day, after his friend in Kentucky had picked up the $687, Fry Guy carried out a second successful transaction, this time worth $432. He would perform the trick again and again that summer, as often as he needed to buy more computer equipment and chemicals. He didn't steal huge amounts of money-- indeed, the sums he took were almost insignificant, just enough for his own needs. But Fry Guy is only one of many, just one of a legion of adolescent computer wizards worldwide, whose ability to crash through high-tech security systems, to circ.u.mvent access controls, and to penetrate files holding sensitive information, is endangering our computer-dependent societies. These technology-obsessed electronic renegades form a distinct subculture. Some steal--though most don't; some look for information; some just like to play with computer systems. Together they probably represent the future of our computer-dependent society. Welcome to the computer underworld--a metaphysical place that exists only in the web of international data communications networks, peopled by electronics wizards who have made it their recreation center, meeting ground, and home. The members of the underworld are mostly adolescents like Fry Guy who prowl through computer systems looking for information, data, links to other webs, and credit card numbers. They are often extraordinarily clever, with an intuitive feel for electronics and telecommunications, and a shared antipathy for ordinary rules and regulations.

The electronics networks were designed to speed communications around the world, to link companies and research centers, and to transfer data from computer to computer. Because they must be accessible to a large number of users, they have been targeted by computer addicts like Fry Guy--sometimes for exploration, sometimes for theft.

Almost every computer system of note has been hacked: the Pentagon, NATO, NASA, universities, military and industrial research laboratories. The cost of the depradations attributed to computer fraud has been estimated at $4 billion each year in the United States alone. And an estimated 85 percent of computer crime is not even reported.

The computer underworld can also be vindictive. In the past five years the number of malicious programs--popularly known as viruses--has increased exponentially. Viruses usually serve no useful purpose: they simply cripple computer systems and destroy data. And yet the underworld that produces them continues to flourish. In a very short time it has become a major threat to the technology-dependent societies of the Western industrial world.

Computer viruses began to spread in 1987, though most of the early bugs were jokes with playful messages, or relatively harmless programs that caused computers to play tunes. They were essentially schoolboyish tricks. But eventually some of the jokes became malicious: later viruses could delete or modify information held on computers, simulate hardware faults, or even wipe data off machines completely.

The most publicized virus of all appeared in 1992. Its arrival was heralded by the FBI, by Britain's New Scotland Yard and by j.a.pan's International Trade Ministry, all of which issued warnings about the bug's potential for damage. It had been programmed to wipe out all data on infected computers on March 6th-- the anniversary of Michelangelo's birth. The virus became known, naturally, as Michelangelo.

It was thought that the bug may have infected as many as 5 million computers worldwide, and that data worth billions of dollars was at risk. This may have been true, but the warnings from police and government agencies, and the subsequent press coverage, caused most companies to take precautions. Computer systems were cleaned out; back-up copies of data were made; the cleverer (or perhaps lazier) users simply reprogrammed their machines so that their internal calendars jumped from March 5th to March 7th, missing the dreaded 6th completely. (It was a perfectly reasonable precaution: Michelangelo will normally only strike when the computer's own calendar registers March 6.) Still, Michelangelo hasn't been eradicated. There are certainly copies of the virus still at large, probably being pa.s.sed on innocently from computer user to computer user. And of course March 6th still comes once a year.

The rise of the computer underworld to the point at which a single malicious program like Michelangelo can cause law enforcement agencies, government ministries, and corporations to take special precautions, when credit bureau information can be stolen and individuals' credit card accounts can be easily plundered, began thirty years ago. Its impetus, curiously enough, was a simple decision by Bell Telephone to replace its human operators with computers.

Chapter 1.

PHREAKING FOR FUN.

The culture of the technological underworld was - formed in the early sixties, at a time when computers were vast pieces of complex machinery used only by big corporations and big government. It grew out of the social revolu- tion that the term the sixties has come to represent, and it remains an antiestablishment, anarchic, and sometimes "New Age" technological movement organized against a background of music, drugs, and the remains of the counterculture.

The goal of the underground was to liberate technology from the controls of state and industry, a feat that was accomplished more by accident than by design. The process began not with computers but with a fad that later became known as phreaking--a play on the wordsfreak, phone, andfree. In the beginning phreaking was a simple pastime: its purpose was nothing more than the manipulation of the Bell Telephone system in the United States, where most phreakers lived, for free long-distance phone calls.

Most of the earliest phreakers happened to be blind children, in part because it was a natural hobby for unsighted lonely youngsters. Phreaking was something they could excel at: you didn't need sight to phreak, just hearing and a talent for electronics.

Phreaking exploited the holes in Bell's long-distance, directdial system. "Ma Bell" was the company the counterculture both loved and loathed: it allowed communication, but at a price. Thus, ripping off the phone company was liberating technology, and not really criminal.

Phreakers had been carrying on their activities for almost a decade, forming an underground community of electronic pirates long before the American public had heard about them. In October 1971 Esquire magazine heralded the phreaker craze in an article by Ron Rosenbaum ent.i.tled "The Secrets of the Little Blue Box,"

the first account of phreaking in a ma.s.s-circulation publication, and still the only article to trace its beginnings. It was also undoubtedly the princ.i.p.al popularizer of the movement. But of course Rosenbaum was only the messenger; the subculture existed before he wrote about it and would have continued to grow even if the article had never been published. Nonetheless, his piece had an extraordinary impact: until then most Americans had thought of the phone, if they thought of it at all, as an unattractive lump of metal and plastic that sat on a desk and could be used to make and receive calls. That it was also the gateway to an Alice-in-Wonderland world where the user controlled the phone company and not vice versa was a revelation. Rosenbaum himself acknowledges that the revelations contained in his story had far more impact than he had expected at the time.

The inspiration for the first generation of phreakers was said to be a man known as Mark Bernay (though that wasn't his real name). Bernay was identified in Rosenbaum's article as a sort of electronic Pied Piper who traveled up and down the West Coast of the United States, pasting stickers in phone booths, inviting everyone to share his discovery of the mysteries of "loop-around- pairs," a mechanism that allowed users to make toll-free calls.

Bernay himself found out about loop-around-pairs from a friendly telephone company engineer, who explained that within the millions of connections and interlinked local exchanges of what in those days made up the Bell network there were test numbers used by engineers to check connections between the exchanges. These numbers often occurred in consecutive pairs, say (213)-9001 and (213)- 9002, and were wired together so that a caller to one number was automatically looped around to the other. Hence the name, loop-around-pairs. Bernay publicized the fact that if two people anywhere in the country dialed any set of consecutive test numbers, they could talk together for free. He introduced a whole generation of people to the idea that the phone company wasn't an impregnable fortress: Ma Bell had a very exploitable gap in its derenses that anyone could use, just by knowing the secret. Bernay, steeped in the ethos of the sixties, was a visionary motivated by altruism--as well as by the commonly held belief that the phone system had been magically created to be used by anyone who needed it. The seeds he planted grew, over the next years, into a full-blown social phenomenon.

Legend has it that one of the early users of Bernay's system was a young man in Seattle, who told a blind friend about it, who in turn brought the idea to a winter camp for blind kids in Los Angeles. They dispersed back to their own hometowns and told their friends, who spread the secret so rapidly that within a year blind children throughout the country were linked together by the electronic strands of the Bell system. They had created a sort of community, an electronic clubhouse, and the web they spun across the country had a single purpose: communication. The early phreakers simply wanted to talk to each other without running up huge long-distance bills.

It wasn't long, though, before the means displaced the end, and some of the early phreakers found that the technology of the phone system could provide a lot more fun than could be had by merely calling someone. In a few years phreakers would learn other skills and begin to look deeper. They found a labyrinth of electronic pa.s.sages and hidden sections within the Bell network and began charting it. Then they realized they were really looking at the inside of a computer, that the Bell system was simply a giant network of terminals--known as telephones--with a vast series of switches, wires, and loops stretching all across the country. It was actual place, though it only existed at the end of a phone receiver, a nearly limitless electronic universe accessible by dialing numbers on a phone. And what made this s.p.a.ce open to phreakers was the spread of electronic gadgets that would completely overwhelm the Bell system.

According to Bell Telephone, the first known instance of theft of long-distance telephone service by an electronic device was discovered in 1961, after a local office manager in the company's Pacific Northwest division noticed some inordinately lengthy calls to an out-of-area directory-information number. The calls were from a studio at Was.h.i.+ngton State College, and when Bell's engineers went to investigate, they found what they described as "a strange-looking device on a blue metal cha.s.sis" attached to the phone, which they immediately nicknamed a "blue box."

The color of the device was incidental, but the name stuck. Its purpose was to enable users to make free long-distance calls, and it was a huge advancement on simple loop-around-pairs: not only could the blue box set up calls to any number anywhere, it would also allow the user to roam through areas of the Bell system that were off-limits to ordinary subscribers.

The blue box was a direct result of Bell's decision in the mid 1950'S to build its new direct-dial system around multifrequency tones--musical notes generated by dialing that instruct the local exchange to route the call to a specific number. The tones weren't the same as the notes heard when pressing the numbers on a push-b.u.t.ton phone: they were based on twelve electronically generated combinations of six master tones. These tones controlled the whole system: hence they were secret.

Or almost. In 1954 an article ent.i.tled "In-band Signal Frequency Signaling," appeared in the Bell System Technical System Journal, which described the electronic signals used for routing long-distance calls around the country, for "call completion" (hanging up), and for billing. The phone company then released the rest of its secrets when the November 1960 issue of the same journal described the frequencies of the tones used to dial the numbers.

The journal was intended only for Bell's own technical staff, but the company had apparently forgotten that most engineering colleges subscribed to it as well. The articles proved to be the combination to Bell's safe. Belatedly realizing its error, Bell tried to recall the two issues. But they had already become collectors' items, endlessly photocopied and pa.s.sed around among engineering students all over the country.

Once Bell's tone system was known, it was relatively simple for engineering students to reproduce the tones, and then--by knowing the signaling methods--to employ them to get around the billing system. The early blue boxes used vacuum tubes (the forerunners of transistors) and were just slightly larger than the telephones they were connected to. They were really nothing more than a device that reproduced Bell's multifrequency tones, and for that reason hard-core phreakers called them MF-ers--for multifrequency transmitters. (The acronym was also understood to stand for "motherf.u.c.kers," because they were used to f.u.c.k around with Ma Bell.) Engineering students have always been notorious for attempting to rip off the phone company. In the late 1950S Bell was making strenuous efforts to stamp out a device that much later was nicknamed the red box--presumably to distinguish it from the blue box. The red box was a primitive gizmo, often no more than an army-surplus field telephone or a modified standard phone linked to an operating Bell set. Legend has it that engineering students would wire up a red box for Mom and Dad before they left for college so that they could call home for free. Technically very simple, red boxes employed a switch that would send a signal to the local telephone office to indicate that the phone had been picked up. But the signal was momentary, just long enough to alert the local office and cause the ringing to stop, but not long enough to send the signal to the telephone office in the city where the call was originated. That was the trick: the billing was set up in the originating office, and to the originating office it would seem as though the phone was still ringing. When Pop took his finger off the switch on the box, he and Junior could talk free of charge.

The red boxes had one serious drawback: the phone company could become suspicious if it found that Junior had ostensibly spent a half an hour listening to the phone ring back at the family homestead. A more obvious problem was that Mom and Pop--if one believes the legend that red boxes were used by college kids to call home--would quickly tire of their role in ripping off the phone company only to make it easier for Junior to call and ask for more money.

Inevitably there were other boxes, too, all exploiting other holes in the Bell system. A later variation of the red box, sometimes called a black box, was popular with bookies. It caused the ringing to cease prior to the phone being picked up, thereby preventing the originating offlce from billing the call. There was also another sort of red box that imitated the sound of coins being dropped into the slot on pay phones. It was used to convince operators that a call was being paid for.

The blue box, however, was the most sophisticated of all. It put users directly in control of long-distance switching equipment. To avoid toll-call charges, users of blue boxes would dial free numbers--out-of-area directory enquiries or commercial 1-800 numbers--then reroute the call by using the tones in the MF-er.

This is how it worked: long-distance calls are first routed through a subscriber's own local telephone office. The first digits tell the office that the call is long-distance, and it is switched to an idle long-distance line. An idle line emits a constant 2600-cycle whistling tone, the signal that it is ready to receive a call. As the caller finishes dialing the desired number--called the address digits--the call is completed--all of which takes place in the time it takes to punch in the number.

At the local office, billing begins when the long-distance call is answered and ends when the caller puts his receiver down. The act of hanging up is the signal to the local office that the call is completed. The local office then tells the line that it can process any other call by sending it the same 2600-cycle tone, and the line begins emitting the tone again.

A phreaker made his free call by first accessing, say, the 1-800 number for Holiday Inn. His local office noted that it was processing a long-distance call, found an idly whistling line, and marked the call down as routed to a free number. At that point, before Holiday Inn answered, the phreaker pressed a b.u.t.ton on his MF-er, which reproduced Bell's 2600-cycle whistle. This signified that the Holiday Inn call had been completed--or that the caller had hung up prior to getting an answer--and it stood by to accept another call.

But at the local office no hanging-up signal had been received; hence the local office presumed the Holiday Inn call was still going through. The phreaker, still connected to a patiently whistling long-distance line, then punched in the address digits of any number he wanted to be connected to, while his local office a.s.sumed that he was really making a free call.

Blue boxes could also link into forbidden areas in the Bell system. Users of MF-ers soon discovered that having a merrily whistling trunk line at their disposal could open many more possibilities than just free phone calls: they could dial into phonecompany test switches, to long-distance route operators, and into conference lines--which meant they could set up their own phreaker conference calls. Quite simply, possession of a blue box gave the user the same control and access as a Bell operator. When operator-controlled dialing to Europe was introduced in 1963, phreakers with MF-ers found they could direct-dial across the Atlantic, something ordinary subscribers couldn't do until 1970.

The only real flaw with blue boxes was that Bell Telephone's accounts department might become suspicious of subscribers who seemed to spend a lot of time connected to the 1-800 numbers of, say, Holiday Inn or the army recruiting office and might begin monitoring the line. Phreaking, after all, was technically theft of service, and phreakers could be prosecuted under various state and federal laws.

To get around this, canny phreakers began to use public phone booths, preferably isolated ones. The phone company could hardly monitor every public telephone in the United States, and even when the accounts department realized that a particular pay phone had been used suspiciously, the phreaker would have long since disappeared.

By the late 1960s blue boxes had become smaller and more portable. The bulky vacuum tubes mounted on a metal cha.s.sis had been replaced by transistors in slim boxes only as large as their keypads. Some were built to look like cigarette packs or transistor radios. Cleverer ones--probably used by drug dealers or bookies--were actually working transistor radios that concealed the components of an operational blue box within their wiring.

What made Bell's technology particularly vulnerable was that almost anything musical could be used to reproduce the tone frequencies. Musical instruments such as flutes, horns, or organs could be made to re-create Bell's notes, which could then be taped, and a simple ca.s.sette player could serve as a primitive MF device. One of the easiest ways to make a free call was to record the tones for a desired number in the correct sequence onto a ca.s.sette tape, go to a phone, and play the tape back into the mouthpiece. To Bell's exasperation, some people could even make free phone calls just by whistling.

Joe Engressia, the original whistling phreaker, was blind, and was said to have been born with perfect pitch. As a child he became fascinated by phones: he liked to dial nonworking numbers around the country just to listen to the recording say, "This number is not in service." When he was eight, he was accidentally introduced to the theory of multifrequency tones, though he didn't realize it at the time. While listening to an out-of-service tape in Los Angeles, he began whistling and the phone went dead. He tried it again, and the same thing happened. Then he phoned his local office and reportedly said, "I'm Joe. I'm eight years old and I want to know why when I whistle this tune, the line clicks off."

The engineer told Joe about what was sometimes known as talk-off, a phenomenon that happened occasionally when one party to a conversation began whistling and accidentally hit a 2600-cycle tone. That could make the line think that the caller had hung up, and cause it to go dead. Joe didn't understand the explanation then, but within a few years he would probably know more about it than the engineer.

Joe became famous in 1971 when Ron Rosenbaum catalogued his phreaking skills in the Esquire article. But he had first come to public attention two years earlier, when he was discovered whistling into a pay phone at the University of South Florida. Joe, by this time a twenty-year-old university student, had mastered the science of multifrequency tones and, with perfect pitch, could simply whistle the 2600-cycle note down the line, and then whistle up any phone number he wanted to call. The local telephone company, determined to stamp out phreaking, had publicized the case, and Joe's college had disciplined him. Later, realizing that he was too well known to the authorities to continue phreaking in Florida, he moved on to Memphis, which was where Rosenbaum found him.

In 1970 Joe was living in a small room surrounded by the paraphernalia of phreaking. Even more than phreaking, however, Joe's real obsession was the phone system itself. His ambition, he told Rosenbaum, was to work for Ma Bell. He was in love with the phone system, and his hobby, he claimed, was something he called phone tripping: he liked to visit telephone switching stations and quiz the company engineers about the workings of the system. Often he knew more than they did. Being blind, he couldn't see anything, but he would run his hands down the ma.s.ses of wiring coiled around the banks of circuitry. He could learn how the links were made just by feeling his way through the connections in the wiring, and in this way, probably gained more knowledge than most sighted visitors.

Joe had moved to Tennessee because that state had some interesting independent phone districts. Like many phreakers, Joe was fascinated by the independents-- small, private phone companies not controlled by Bell--because of their idiosyncrasies. Though all of the independents were linked to Bell as part of the larger North American phone network, they often used different equipment (some of it older), or had oddities within the system that phreakers liked to explore.

By that time the really topflight phreakers were more interested in exploring than making free calls. They had discovered that the system, with all of its links, connections, and switches, was like a giant electronic playground, with tunnels from one section to another, pathways that could take calls from North America to Europe and back again, and links that could reach satellites capable of beaming calls anywhere in the world.

One of the early celebrated figures was a New York-based phreaker who used his blue box to call his girlfriend in Boston on weekends--but never directly. First he would call a 1-800 number somewhere in the country, skip out of it onto the international operator's circuit, and surface in Rome, where he would redirect the call to an operator in Hamburg. The Hamburg operator would a.s.sume the call originated in Rome and accept the instructions to patch it to Boston. Then the phreaker would speak to his girlfriend, his voice bouncing across the Atlantic to a switch in Rome, up to Hamburg, and then back to Boston via satellite. The delay would have made conversation difficult, but, of course, conversation was never the point.