Defeating Your Electronic Shackles

An Israeli prisoner that was forced to wear an electronic shackle that verifies he doesn't violate his home arrest, had outsmarted the device (original article is in Hebrew).
The shackle monitors the suspects relative location and if the suspect leaves a defined detention area, the device signals through the telephone line to the local police. How did he defeat the system ? He stopped paying his telephone bills and his line was disconnected...

From Schneier's