The simplest answer for everyone - just don't log in again. The webmaster has the ability to shut down accounts, but that's typically reserved for banned posters that are no longer welcome here.We recognize that this place isn't for everyone. But cancelling an account is just a bunch of extra hoops for folks to jump through. And this way, if you decide at some point that you'd like to give this place another try, you can easily do so.
This poster also points out another valuable lessons about message forums (not just this one). If you can read messages without having to register, take advantage of the opportunity to figure out whether or not a forum is right for you before registering.