'You can monitor what's going on inside, so you can hear the lift saying 'you are on the third floor'. The speaker inside the lift has an extension like a phone would and you can dial the phone inside the lifts. 'The elevators or lifts inside have emergency telephones and these telephones are attached to the PBX. He's British, but is using an alias, 'Belial', and I don't know his real name.
'Let's say a shopping center,' says the hacker I'm talking to online.
Cartoon from Volume 1, Issue 1 of Telephone Electronics Line (1974), a newsletter devoted to phone phreaking ()