Allow me to introduce Phil Lapsey's non-fictional 2013 narrative Exploding the Phone: The Untold Story of the Teenagers and Outlaws Who Hacked Ma Bell with some personal observations relevant to his research:
Back in the 1970s, in the San Fernando Valley just north of Los Angeles, you could call a free-of-charge telephone number that read you the current time. What the majority of the users of this service would never realize was that in some circumstances, due to a fluke of the telephone system, you could often hear faint voices in the background, not a part of the computerized recording reciting the time as it progressed. If you listened closely, some of the voices were intelligible, clearly raising their voices to get through to others on the line. They'd call out a telephone number, then follow up with variations on "Call the trunk line!" or "Call the busy signal!"or "Call the loop line!" That's how I was introduced to one tiny pocket of the much larger phenomenon that came to be called Phone Phreaking, and spent untold hours "hacking" the same still antiquated telephone system as more sophisticated - and often genius - kids with innate engineering talent and an inexhaustible curiosity about things mechanical or electric in their everyday worlds. Like these other kids - I was in my late teens or early twenties when I started - I explored the bizarre nature of Ma Bell's ancient switching system solely by searching out these weird test lines, loop lines, and on-again off-again busy signals because, like them, I was intensely curious yet even more intensely drawn into myself, a lifelong loner others kids always saw as different, as socially awkward as anyone you'd ever meet. Wandering the maze of numbers that allowed people like myself to connect anonymously with others like me was, it felt, perfectly natural, and great fun besides! I discovered by "random" dialing similar numbers that I could find dozens of others that acted like the time line did, and relatively fewer numbers that would allow a one on one private conversation, and fewer yet that were true party lines where dozens of kids could be heard clearly having conversations in and around other voices, calling out the numbers to other busy signals, loops, or party lines, or just providing their own surreal monologue to the mix. My favorite to this day was a guy who repeated, in measured tones that allowed him to stand out above the crowd, the phrases "I LOVE bodacious ta-tas! Do YOU love bodacious ta-tas?" Characters like this added a certain spice - or if it obscured someone yelling out a number you wanted, a certain bit of annoyance - to the mix.
In Exploding the Phone Lapsey doesn't mention the time line - and this surprises me given its role in bringing young people together on various types of private and party lines here in California. How he never encountered anyone using loop and party lines in Southern California that might bring it up is beyond me. But he does explicate the nature of some of these lines. The "trunk line" time callers might refer to was more than likely one of the myriad test lines found throughout the telephone system for engineers and techs to use in performing various maintenance tasks. The "busy signal" could be an identically functioning party line, where any number of people might join in - free of any charges - but constrained by having to talk over a constant busy signal. Naturally, a line without a busy signal was much preferred - and much more rare. The other item a busy signal might refer to was one half of a loop line, a pair of lines connected together for technical purposes but available to anyone dialing the two numbers. One number, say 555-1118, would have a busy signal. Calling that, you'd wait on the line for someone to call the other number, 555-1119. Since you were already on 1118, he or she would not hear a busy signal, and because they had made the connection as half of a private call, your busy signal would drop out and you would both be able to speak with one another just like any other phone line. Where's the fun in that, you ask? The answer is simple: Anonymity. Today on the internet you can join a chat and be anyone you like. Back then on a private line you could do the same. The other party had no idea who you were or what your appearance was, other than what you told them. You could say and do anything you liked, if your private phone buddy was willing, in complete privacy (assuming nobody else was at home with either party). You can guess how addictive that might be for the lonely kind of personalities that would seek out these phone anomalies in the first place. You could be a nerd and yet still have some kind of social interaction - possibly more so than those you were capable of having in public. And sometimes the person on the other end had more numbers to call. Hacking the phone system could take up hours of your time, make you late for work, and cut you off from friends or family trying to reach you and only getting a busy signal - the regular kind, not the chatty sort.
Lapsey's work is based on hundreds of hours of conversations with the personalities who first discovered and learned to seriously exploit the sprawling United States phone system and the ways it's electro-mechanical switches were arranged to route calls throughout the country and the world. Far from content to "just" exercise their nascent social muscles via anomalous private or party lines, these men, a handful of who were not just socially inept and isolated, but blind as well, literally could not help themselves from exploring this new world once they had discovered it. The kind of four year old that tries to stick bobby pins in electrical sockets often turned into the kind of teenager that sticks figurative pins into the weird apparatus of what we all called The Phone Company to see what would happen. (Lapsey even mentions the satiric James Coburn-starring cult film The President's Analysis, whose ultimate villain is - you guessed it - The Phone Company, run by audio-animatronic figures right out of a Disney exhibit, exhorting you to submit to their will as calmly as Disney's Lincoln reciting the Gettysburg Address). Lapsey also spoke with most of the law enforcement and telephone security officers tasked with finding and often prosecuting the phone hackers. And, of course, some of the lawyers who did the prosecuting. It's uncertain who first discovered the efficacy of billing by the minute - AT&T or lawyers. With an ancient infrastructure providing openings everywhere for mischief and crime alike, AT&T was ceratinly destined to employ a lot of lawyers.
The self-styled phone phreaks pushed the bounds of propriety and legality - frequently crossing either or both in their quest to learn the system. What worked best for them - and against Ma Bell - was the open nature of the system, and the company's own early naivete about what they had created. Caring only that the system worked well enough to build a telecommunications empire that served its customers very efficiently for the most part, Bell Labs and their manufacturing arm Western Electric were as open as the system itself, publishing technical articles in journals of the day that enterprising and curious people like the two Steves - Wozniak and Jobs, eventual creators of the Apple computer - might simply look up in the library. Coupled with the accidental discovery, made independently by several different phreaks over time, that one could duplicate the tones that governed call routing and billing inside the phone system, the technical details such publications offered allowed these phone hackers to learn the system inside and out. Once in, they bravely explored the system, often imitating technical personnel in order to convince Bell operators and tech support to do their bidding and reveal new secrets they could never have found by random exploration.
At one end of the spectrum were kids like me, just playing with numbers and lines. Somewhere closer to the other end were these often brilliant engineers at heart going so far as to build equipment that duplicated the phone company's magic signals and moving freely - at no charge - throughout the country's phone lines. And at the farthest end was a mini-spectrum of people, from the initially innocent and almost certainly mentally disturbed John Draper, known as Captain Crunch because his phone hacking began with the toy whistle from a box of that cereal - to organized criminals using the so-called "blue boxes" people like Woz and Jobs were manufacturing - and selling! - to assist in making book.
Lapsey details it all, with valuable background and insight into the phone company's creation and development throughout, right up to the days Ma Bell finally put her foot down and found ways to modernize the Phreaks out of their favorite pastimes. The heyday of phreaking was in the 60s and 70s, following a period of early discovery in the 50s, and something else was going on in parallel with the exploration of the phone company. Similar brilliant young men at this time were exploring the very new world of computers, a story so similar to Lapsey's narrative that Steven Levy's excellent 1984 volume Hackers: Heroes of the Computer Revolution includes a significant foray into phone hacking as well, making it the perfect companion volume to Exploding the Phone. And for international espionage inside the early internet, another fascinating tale is Cliff Stoll's The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage, written in 1989. All three books are, afaik, currently still in print or otherwise easy to find, and essential reading if any of this stuff rings a bell with readers of this review. All highly recommended. [Edit: I also just found out Lapsley's book has it's own web page, including outtakes from the book! Rubs hands together excitedly. More exploring to do!]