That'd be a bit drastic, as there are a lot of supposed spoilers that aren't really spoilers but just educated guesses or outright fabrications. Besides, even the best of us slip now and then in our eagerness and post something that ends up being a spoiler, and it would be hasty to ignore someone for that.

I've learned you'd better have verifiable and notarized proof that you've been spoiled or that a rule has been broken before using the report function, or else.