Beside hacking and close to this term, there is another illegal activity called phreaking. Phreaking is using a computer or other specific device for tricking telephone system. Using phreaking user makes call somewhere and it is paid from another user’s account. It’s kind of phone network cracking.
Phreaker is a the one who manipulates or cracks phones in this way. So called blue box is a tool for phreaking. It’s an electronic device. With it’s help phreaker can create so called 2600Hz tone. Also they could use a miniature tape recorded and play the sound of 2600Hz tone.
Another toll for phreaking was a red box. It could simulate coin deposit so they were used for payphones.
Less known tool but also for phreaking was beige box. Phreaker could use other person’s phone line to make free calls. It was also illegal (and still is).
One more tool – a clear box. It was used to bypass some rules against using pay phones without paying, that means for free. There were some phones, that were very old and they allowed connection with other user only he couldn’t hear caller until the coin was deposited. So the clear box cracked it.
The black box was used for long distance phone call fraud. Black box had enabled calls between rings. It blocked the supervision signal sent by the receiving telephone handset when the call was answered at the receiving end of the call.
All these tools and many more were used during 1960s and 1970s, when long distance calls were very expensive. But all of them were for illegal purposes. Nowadays there is very small number of people that use phreaking because it’s not very effective.