The Rollback feature is a counter-vandalism tool available to Administrators, and users with the Rollbacker permission. The rollback feature allows a user to revert all of the edits by one user on a page, to the last edit by another user. This feature should only be used in reverting edits that are clearly vandalism, and can be requested at FarmVille Wiki:Requests for Permissions#Rollbacker. A list of all users with access to the rollback feature can be found at Special:Listusers/rollback.