> If I ran a forum for a number of years, and a person decided to close their account, that'd be fine. But if they then said that I need to remove _all of their posts_, that's really shitty.
> It would destroy the usefulness of a forum.
Couldn't you just anonymize their posts, for instance by updating their username to something like "Deleted User"? Wouldn't you be fine as long as there wasn't anything left to link them to their real identity?