#1 should be inconsiderate and entitled potheads deciding that not only do marijuana laws not apply to them, but neither do indoor smoking laws.
Oh c'mon man where do you want them to go puff? I can feel you on the cigarettes, but smoking a bit of weed is no big deal. If they're smoking blunts that's different though. In my experience a concert full of stoned people is a much nicer time than one filled with drunkards.