Anyone can revert vandalism and bad-faith edits, but it takes a couple of clicks in the page history to get it done. Users with the rollback tool can undo bad edits with one click, by using the rollback link on diff pages, user contributions list, or the list of recent changes.
Rollbacks may not enforce the rules. Warning users in the stead of an administrator or designated moderator is considered mini-modding, and is against the rules for any user, rollback or not. Once a rule violation is found and edited out, rollbacks must report the violation to an administrator so the user can be warned properly.
However, rollbacks may sometimes be granted the privilege to enforce certain policies by the site administration. Currently, rollbacks may enforce the wiki's policy on leaks and spoilers.
Causes for demotion
Rollbacks are granted their privileges due to being active editors, which is considered editing at least once every other day. If a rollback becomes inactive, they will receive a notice that they may be demoted for inactivity. Failure to become active again may lead to a demotion.
Rule violations and inappropriate behavior
Rollbacks are regarded as trusted editors, so if a rollback presents inappropriate behavior or violates the wiki's rules, a demotion may be considered depending on the violation and its severity.
If a rollback is demoted, they can always re-apply for their position by posting on the rollback application thread. Rollbacks demoted for rule violations and inappropriate behavior will need to wait some time before re-applying for their position and prove to the administration that they have improved their behavior.