In the early early days of telephone hacking (phone phreaking) a guy named John Draper discovered that the toy whistle found in a box of Cap'n Crunch cereal wou

In the early early days of telephone hacking (phone phreaking) a guy named John Draper discovered that the toy whistle found in a box of Cap'n Crunch cereal would emit a tone at precisely 2600 Hz. This frequency was used by The Bell System to issue call routing instructions. With it, you could make free long-distance calls around the world. Some via satellite.