Username or EmailPassword
I'd agree fully that the feeling of anonymity lowers inibitions just like the drink and people suddely feel they can behave in ways they would never behave normally. It is the "Liquid Courage" of modern communication. We used to see lots of Keyboard Courage in the old BBS scene that preceded the popular explosion of the Internet scene. It can be seen in archives of the Usnet and other early mailing list forums.
I think people will generally exploit any medium that provides a sense of anonymity or abstraction from face to face conversation.