Editing Blue box (section)

===Discovery and early use===
Before the technical details were published, many users discovered unintentionally, and to their annoyance, that a 2600 [[Hertz|Hz]] tone played into the caller's handset would cause a [[long-distance calling|long-distance call]] to disconnect. The 2600{{nbs}}Hz tone might be present if the caller were whistling into the telephone microphone while waiting for the called party to answer. Upon detecting the tone from the caller's end, the receiving signaling unit sent an on hook status to the connected equipment, which disconnected the call from that point forward, as if the caller had hung up.

Among the earliest to discover this effect was [[Joybubbles|Joe Engressia]], known as ''Joybubbles'', who accidentally discovered it at the age of seven by [[whistling]]. He became fascinated with the phone network, and over the next decade had built up a considerable base of knowledge about the system and how to place calls using the control tones.{{Citation needed|date=January 2022}} He and other [[phone phreak]]s, such as "[[Bill from New York]]" and "The Glitch", trained themselves to whistle 2600{{nbs}}Hz to reset a trunk line. They also learned how to route telephone calls by flashing, that is using very short pulses of the on-hook signal, to send routing instructions.

At one point in the 1960s, packages of the [[Cap'n Crunch]] breakfast cereal included a free gift: a small whistle that, by coincidence, generated a 2600{{nbs}}Hz tone when one of the whistle's two holes was covered.<ref>{{Cite book|url=https://books.google.com/books?id=kYFzBgAAQBAJ&q=blue+box+Cap'n+Crunch+breakfast+cereal&pg=PA7|title=Cyber Attack|first1=Martin|last1=Gitlin|first2=Margaret J.|last2=Goldstein|date=December 6, 2015|publisher=Twenty-First Century Books|via=Google Books|isbn=9781467725125}}</ref> The phreaker [[John Draper]] adopted his nickname "Captain Crunch" from this whistle.<ref>{{Cite web|url=https://www.popularmechanics.com/technology/a20762221/an-early-hacker-used-a-cereal-box-whistle-to-take-over-phone-lines/|title=An Early Hacker Used a Cereal Box Whistle to Take Over Phone Lines|first=Laura|last=Yan|date=October 22, 2019|website=Popular Mechanics}}</ref>

The [[Toll-free_telephone_number#United_States|"toll free" 800 service]] was launched in 1967 and gave the hackers easy numbers to call. The user would generally choose a number in the target area and then use it as above. Even if billing information were generated, it would be to a 1-800 number and thus free of charge. As before, the remote system would notice a call going to the ultimate non-free number, but could not match the other end.