Additionally, if the user reach us to delete their quoted posts another unique thing we do is that we change the ownership of the post... We have "bot accounts" in the forum, that no one owns them, and I created these accounts for this purpose...
Because it is -almost always- about user not wanting to be associated with that post, not about giving out personal info... So, when I tell them that "I am changing the owner of the post and this post will not be associated with you again" they all have been OK with this solution...