Have you ever Googled yourself? Maybe run a web search on your screen name? It's a good idea, since you can find a lot of information that way about yourself and what others might know about you.
I like to search for my internet screen names whenever I wonder if I've forgotten to update one of my profiles. It also helps me keep track of where my information is stored. I made a list of all the web sites where I had a profile, and it was easy to see a pattern in the types of sites I like to visit.
The one annoying part is how many websites like to rip off my youtube page, causing thousands of results on web pages I've never been to. Still, it's a great way to keep track of yourself and your information. Hey, maybe you should run a web search on one of your friends. You never know what you might find out about them.