How would you expect this kind of feature to work?

In particular, what would you expect to happen to posts you created?

What about threads you created which other people have also posted in?

What about other people's posts that have quoted parts of your posts?

I think that one should expect data about their online activity to:

+ Disappear if persistence is what you would prefer.

+ To persist if disappearance is what would you prefer.

+ To be tied to personally identifying information if anonymity is what you would prefer.

+ To be anonymous if you would prefer it to be bound to personally identifying information.

vBulletin deserves credit for being a slight improvement over Usenet. There's a reason StackOverflow, Reddit, and even HN don't use it.

The same applies to other forum software as well, like phpBB and IP.Board.

The only way to get your account deleted is to contact the site administrator. Sometimes though, they won't accept it because it may break the forum conversation, so the next best thing is to rename your account to something like invisible unicode characters.

If i fill in just a 'username' & password fields on a forum, who owns it? -is that my data or is it more analagous to the key cards my employer provides me with to gain access to the building?

also.. I believe the safest way to maintain a 'never email me again' list is to keep just the email address indefinitely.

Also is it vBulletins data to delete without approval from the web admin? I don't believe so. This is most likely an issue of what web/forum masters want and not what makes the most consumer-friendly sense.

Wordpress.com doesn't either (and I was very surprised by this):

http://en.support.wordpress.com/deleting-accounts/

What about an MD5 of the nickname, blanking the associated email?

If you want to get meta, neither does Hacker News..