The only post of mine to receive any +/- points received a +1 whilst simultaneously receiving a -1 for allegedly being inflammatory. Either I have the ability to be informatively inflammatory, or the report button should be renamed "I'm having a hissy fit about this post."
To be honest, I thought that it was a waste of time, and knowing who is raising or lowering your reputation is likely to cause a tit for tat war. If we were voting, I'd pick the "who cares" option.
Hans