I'm a bit confused. I have my comments systems locked down and on a few sites require users to log in to comment and on mobodojo I allow unregistered readers to comment, though I don't allow any links and I pay close attention to possible spam. I'm happy with the control I have.
What I don't understand is why I'm starting to get fake user registrations. They're obvious, too, as many of them are in jibberish. What purpose does this serve? Am I experiencing an exploit in progress? Its not like they can post or get easier access to comments. I don't even allow registered users any additional freedoms.