If zombie reports any more useless things, you can go ahead and report him.
I've already Pmed him to stop (an offical verbal warn). .. His reply was stupid. But it didn't sound like he would stop. So, go ahead and warn him later.
I don't want people to be scared to warn, but perhaps you should say only if you see a clear violation of the ToS (which is also vague unfortunately). Although it might take us the effort of clicking here, then delete, Zombie also had to type his message up as well.