Is it normal to sock people in the back of their heads at rock shows?

Nothing rev's my motor up like heavy metal & a couple of monster energy drinks-
The mix of the two makes me go buck wild like a horse who just got his nuts chop't off-
Once the heavy music makes my head bop I know it's time to make other heads bop "with my fist" & when I'm done & the music has stop't I pray for the back of their little emo heads too heal up quick so I don't get busted by the karma police.