What I'm wondering is.. Would there be a seperate negative props stat or would it just minus one from your total props? And more importantly, supposing that someone get's pissed off at you, what is going to stop them from finding a hundred of your past posts and negging them all?
You can be allowed a certain amount of props and negative props you can give out in a 24 hour period.
That amount can also be based on how long you've been a member and/or your total prop count, total posts, etc.
If you have a negative prop total, or zero, you will not be allowed to negative prop someone else.
All of those things I've seen on other sites as well so I know they are doable.