Quote from: VignacSecond

That's exist ?

It does not. However, you can accomplish this with an SQL query on the database.

Code

DELETE FROM `posts` WHERE userID=#;

Just replace the # with the ID of the user you are clearing posts for.
If they created any topics you want gone then you'll have to run another query:

Code

DELETE FROM `topics` WHERE creatorUserID=#;

You'll probably want to avoid doing this unless you have to, because there will be minor side effects since the normal deletion process for posts and threads also involves correcting some index information which is difficult to do manually.