Board Thread:Support Requests - Community Management/@comment-452-20141015211337/@comment-24916335-20141015211704

First you should contact them. Tell them on their wall that they need to stop doing it as they are not setting a good example which is what admins should do. You do not have to disable achievements just because of some immature users.

It wouldn't be abusing of power if you warn them first, besides, this isn't allowed in any wiki. So like I said, try talking to them, if this continues, you at least warned them.