Why Do People Pretend To Comment As Someone Else?

I received an email from Tyler Cruz about comments made on my blog using his name. It seems someone is going around pretending to be him and making lude and rude comments to make Tyler look bad.

One of my ‘haters’ is apparently spoofing at me in your comments. Take a look at Comment Signatures – Yay or Nay for example.

This is one reason why I dislike letting people comment without registering accounts. He is tarnishing my reputation and I’m very angry about it.

Pretending to be someone else bad enough. However, to purposefully use that person’s name to make them look bad is pretty low. I decided to find out if anyone is commenting using my name and found one case. Someone pretended to be me in a comment about John Cow shutting down because of legal problems. The cow exposed him as a fraud but I still wasn’t very happy to see my name being used in a comment that I didn’t make.

My question is what drives some people to do this kind of stuff? Why do people pretend to comment as someone else? Is this a widespread problem? I hope not because I would hate to require people to register before they can comment.