Today I learned...

TIL about switch-hook dialing and abstracting electricity.

https://en.wikipedia.org/wiki/Pulse_dialing#Switch-hook_dialing

As pulse dialing is achieved by interruption of the local loop, it was possible to dial a telephone number by rapidly tapping, i.e. depressing, the switch hook the corresponding number of times for each digit at approximately ten taps per second.[5] However, many telephone makers implemented a slow switch hook release to prevent rapid switching.

In the United Kingdom, it used to be possible to make calls from coin-box phones (payphones) by tapping the switch hook without depositing coins. Unlawfully obtaining a free telephone call was deemed to be a criminal offense of abstracting electricity[6] from the General Post Office, which operated the telephone system and several cases were prosecuted.