There were also some restrictions on lines used for broadcasting purposes, where you could dial in to hear a recorded message. This was used by mostly right wing commentators from the '60s-'80s and sometimes derided as "dial-a-hate."
The lines had to announce the subscriber's name and the recordings could be required to be taken down if found defamatory.
When 900 numbers with paid recordings, like messages from celebrities or gambling advice, became available, they had to announce their fee structures upfront before people were connected to the paid programming.
This is true, but these were side services. The core service of having a phone number was, I think, universal the way having a street address is. I mean not so much legally as in popular imagination. Like you can write fan letters to serial killers on death row, if you wish, and nobody is scandalised that the USPS will deliver your letter like any other.
The lines had to announce the subscriber's name and the recordings could be required to be taken down if found defamatory.
When 900 numbers with paid recordings, like messages from celebrities or gambling advice, became available, they had to announce their fee structures upfront before people were connected to the paid programming.