2600 may refer to any of the following:
The frequency in hertz that AT&T initially used to indicate when a line is free. In 1974, John Draper aka Captain Crunch discovered a breakfast cereal children’s whistle was capable of making this tone. He and others used this technique in conjunction with a blue box to generate the 2600 hertz tone and make free long distance calls around the world. These individuals came to be known as phreaks.
2600 is also a commonly used name for news or information containing information about hacking and phreaking.
The 2600 name commonly associated with the early Atari VCS (Video Computer System) gaming system.
Phreak, Security terms
