You could also argue that the solutions to that are known but not currently widely used. If you were to create an iteration of email where there only people alo

You could also argue that the solutions to that are known but not currently widely used. If you were to create an iteration of email where there only people aloud to email you were the people in your address-book, would that not be a bit like Facebook is now. Identifying people can be done via signing messages with GPG so no one could forge the sender. Having everyone sign messages on NNTP would work too since you could whitelist a set of people or alternatively a black list of known bad people. Forums like this are good, but lack the convenience that a NNTP news reader used to have of having all your conversations in one place.