As much as the TV cartoons influenced my devotion to Cap’n Crunch — which has waned but never truly wilted — there were also free prizes in the boxes which were a bit more high-quality (to a kid’s mind) than other cereal-box prizes. They’d have comic books and all sorts of great things. One famous free prize was a toy whistle called a bosun’s whistle. The whistle, at some point, gave rise to the famous legend of John Draper, a.K.a the hacker Captain Crunch. He is said to have discovered that the whistle, when you blew it, produced a nearly precise 2600 Hz tone. If you dialed a long distance number and then blew the whistle into the mouthpiece, this tone would terminate the call. At least, it would terminate the call as far as AT&T knew. In reality, the line on the other end would remain open, allowing you to continue the call without being charged for it. The technical reason for this is beyond my understanding (I’m just regurgitating my research), but it has something to do with sending the tone down a long-distance trunk, which would terminate the call, and then seize another trunk for reuse once the tone stopped.
See also: What Was Cap’n Crunch’s Full Name?
This practice gave rise to what was called blueboxing, which was the first automated tool fraud technique used to defraud phone companies. A box (the first one discovered was blue) was used to get free long-distance and international calls using 800 numbers, employing not only the 2600 Hz tone but a series of tones called “multifrequency” or MF tones. Steve Wozniak and Steve Jobs are said to have made their own bluebox before they made the Apple computer and John Draper was a big technical adviser to them and others, called “phone phreaks.” He also became one of the first Apple employees.
Although John Draper is the subject of the legend, he is not the first person to realize that a 2600 Hz tone could be used to get free calls. There were also a group of blind phreakers, who, it is claimed, had perfect pitch and could produce this tone themselves by whistling into the phone. Joe Engressia, a.k.a. Joybubbles was one of these. The blue box wasn’t the last gadget the phone phreaks community made, and this was the first form of “hacking” which later became internet hacking.