The thing is that in the absence of the likes of facebook you usually don't turn over your data and accounts. You just typically give them username: Somerubbish password: 123whatever and that's it.

No, I don't. I use a password manager. I promise I'm not being obtuse. That is what I do. I create an account, and add it to KeePass. Because I never know when I will need it later, even if I don't think I will.