The evolution of identity on the internet is an interesting one. In the 90s, using your real name was considered absurd. Now it's the standard. Maybe you'll also have a pseudonym in your handle, but the majority of people use their real name on most of their social media.
Certain communities retain pseudonymous, such as a good portion of Hacker News and Reddit. Although, I see many people posting more and more revealing information on Reddit these days, as it leans towards becoming like Twitter and Facebook.