Its part if the forum software and the philosophy of the people who made it. (Its an open source project)
If someone posts a topic and then someone else responds the whole thing is now owned by the community not the original poster.
If anything is posted that is offensive admins can delete but thats not how we want to handle marking things in buy and sell as sold.
Mark the title of the post as SOLD (or DELISTED) is sufficient to signal it is no longer for sale.
There is no need to raze the earth if all evidence it existed.