I have never flagged a post. There has been a couple that I was tempted to flag, but I don't feel that it is appropriate for me to make that judgement.

I think if somebody is stealing someone elses identity, or committing plagiarism they should be flagged.

I've seen some posts that may be inappropriate for children.

I like the idea where a committee would make a value judgement as to what should be flagged. A committee comprised of people tha completely understand the rules. I believe this would eliminate some of the questionable flagging.