It was another case of individuality by conformity that came out of the '80s Punk Rock crowd. Their slogan was, "Don't drink/ don't smoke/ don't f*ck."
For the most part, I believe that they stayed to their own groups and hangouts. In the worst case, they roamed clubs and house parties like skinheads, chose people who did not hold to their beliefs and attacked them. Sometimes they'd carve an "X" in your forehead if they didn't like you or if you were a Straight Edger that fell away and drank, smoked or f*cked.
They used a knife to carve an x in the heads of folks?