The flag button doesn't appear until you get to the reply page - making sure people know they can flag comments would be a good start. Also, 20% of karma isn't

The flag button doesn't appear until you get to the reply page - making sure people know they can flag comments would be a good start. Also, 20% of karma isn't very useful for troll / griefers on throwaway accounts. A fixed value (-100?) might be better.