I think people have to earn their right to warn, since so many people are doing it just so the points go up on their go. Also if you warn too much you lose the right. I think that is the only fair way.
As you might probably be able to tell, I'm quite pissed off about it 'cause it happens loads and loads of times to me and so many other people, If you agree with what i have said please reply to this thing?? And hopefully put a stop to this.
Oh and sorry if there is already a thread like this, i usually can't be bothered to look through until i find one.