Back in the pre-internet, pre-cell phone days, the largest national communications network was the telephone. Using a rotary dial and some patience, you could reach someone on the other side of the country in just a few minutes, which was a revelation. The system worked amazingly well but it had a major security flaw, and this flaw made the network the personal playground of an underground band of "phone phreaks."
The phreaks discovered that they could re-route calls and bypass the system, using whistles, taps, and brazen ingenuity. College students, blind teenage prodigies, and various outlaw characters (including Steve Wozniak and Steve Jobs) created "blue boxes" for their underground operations, which, according to Jobs, presaged the creation of Apple Computers.
Eventually, Ma Bell and the FBI caught up with them and everything unraveled...but not before the phreaks left their mark on the industry. Phil Lapsley's history of that era reads like the very best of espionage fiction except that it's true. Modern technology makes such a David and Goliath story unlikely to ever happen again -- and Exploding the Phone uncovers the whole fascinating secret history.