"You mean any random IP logging in from the Spratly Island can take off a tag and we have no power to fix the vandalism?"
 Yes.
 The alternative would be for the person reverting to make value judgements on whether something was vandalism or not. As your recent edit history shows that you equate any anonymity with vandalism, that's not a decision you can be trusted with.
 The downside requires you to press the AfD button, not the revert button. Get over it.