I do much the same. Mostly it's a free speech thing. I don't want to feel like expressing my opinion on the web is going to haunt my life. For example, I wouldn't want to post political stuff connected to my real name because if I had strong opinions on something pro or con and a prospecitve employer found out about it, it means I don't work there. It's just the way things are headed -- employers demand your online life, because they want to find a drunk picture of you or some controversial opinion or something so having said opinions connected to your name is potentially problematic.