In my experience, I always find the loudest and rudest of 'fans' are often fans of the poorest act. I recently played a gig in London and shared the bill with a few other acts. The people who were talking during all the sets were fans of a performer who was very sub-standard… this seems to be a pretty common theme.

Anyway, I always find approaching these people and asking them to be quiet to their faces is the best way of making them shut up!