As you should know by looking at the bottom of the left column on this page, I have a Site Meter which records information about visitors. I mainly use this to figure out who is linking to my blog. If you are using a webmail account and your username is in the URL of your program, you are sending me your username when you click on the link to my site from the email somebody sent you that said "Hey, check out this O'Hara idiot." Especially considering how so many usernames are based off actual names, if you do this, chances are that I now know your real name.
Surely, you can trust Garrett O'Hara; I have nothing to gain from knowing your name save a few ego points. But the rest of the Internet is also able to see these statistics, meaning you are telling the entire world exactly when you logged into my website, along with location, IP address, web browser, and more. For the sake of your own privacy, stop clicking on links in emails; copy and paste the URL into a new browser window.
So far I have positively identified two UA students and a lawyer from Beaumont, Texas (Cade Bernsen's hometown) using this method. I even have pictures of you. For your own sake, knock it off. And don't sue me.
Update: Make that three positively identified UA students.