> * The callee can always clear calls In the 1980s at school, the phone system in the dorms was a private system (you could connect to the public system by dia

> * The callee can always clear calls In the 1980s at school, the phone system in the dorms was a private system (you could connect to the public system by dialing 9 first). In this system, a call was not terminated until the originating side disconnected. So a common prank was to call someone, then not hang up. Now their phone was unusable.