When I started on the Internet, way back when, it was almost unheard of to use one's real name online. Yes, there were a lot of people who hid behind an online persona to say what they wished without fear of consequences. Also there were major security issues. For me, it became a habit - seeing the Internet as a place where, for personal safety, I did not give out any real personal information.
When I first started on HubPages, I treated it as a site where I could write about personal things, about anything, and out of long habit, I brought a persona with me from another site. I used an avatar because I would then have no sooner put my picture online than have flown to the moon. As well, the sketch has meaning for me.
Now though, there are sites where I write professionally and use my name and picture, but it was a big step just to put my name online here