That's a criminal offence in the UK (two year prison sentence in some circumstances). Do you have a good feeling for what might count as incitement in those circumstances?
No, they don't. My blog is not all that popular. It has got some programming puzzles, Linux HOW-TOs and stuff. Most of my audience is just my friends.
Of course that is the cynical version of it. But as others have pointed out some people dont like these sort of risk.