@purldator sorry, that was a typo. It was supposed to say remove.
I'm still not quite getting it. When a person chooses to leave, they would hit the download button, download their posts and stuff, and then all of the information related to them would be deleted from the site? All of their posts, chats, and their user account?
No, this would allow them to take their content, not erase it. My forum's TOS (or the draft at least) is explicit in stating that the license they grant to me is 'forever' to make sure the forum's archive is kept intact, and also for any reasons that may arise due to abuse.
I only want a member to be able to download everything, or anything that they participated in (see my second proposal in my OP) if allowed by the OP of the topic.
Chat history would be the only thing erasable if possible after a user downloads a chat's history.