There doesn't seem to be a function to view edit history, or revert the posts. I think the OPs has the final say on their posts. If they modify the posts, they probably have good reasons to do so, and we'll leave them as is. In some cases the posts have significant content from textbook or research articles, and I actually prefer that they be removed. Every once in a while I receive email from copyright holders threatening to sue if some posts were not removed quickly. I assume that the OPs are doing the forum a favor in modifying posts.