daytripper... I recognize your name as that of someone who's posts I valued. I do understand that there could be several reasons why somebody would want their posts to be removed though.
Spores, welcome back! It's as if you've just been baptized brother! Your old life is now but a shadow, burried in the grave that is the water, while you stand here before us; behold, a new soul! The Father, the Son and the Holy Ghost are your witnesses today, AMEN. I mean, I have a request: could you, maybe, possibly, somehow... bring back that recognizable cool avatar you used to have?! That would make my day, thank you.
As for forum software that erases the posts when a user account is deleted: I've seen discussions on websites where some posters were named 'Account removed' or something among those lines. On the other hand, it does make sense that when you delete a user, all related data is erased from the database. According to technical conventions I guess you'd rather disable that account than erase it.
Another thing... where do you guys store your backups? /dev/null or something?
Don't want to sound ungrateful for this great forum or anything, but I've seen a lot of online forums that crashed and didn't have a (recent) backup. Having a working backup plan to me is one of the essential things for a website administrator!