Police officials say gang members have co-opted the fashion statement. Centennial administrators are telling students who shave the lines that they can't return to school until they take care of the problem — by shaving their eyebrows off. Andy Gonzalez, a junior at Centennial, was studying for a test when a security guard approached him and told him to go home. Copyright The Associated Press. It's usually done on one eyebrow but can be done on both, and there could but slits on an eyebrow or just one.
Police: Teens with shaved brows plucked from class; too close to gang ties
This is a way for them to identify each other. People also do these to identify with a group if a whole clique does eyebrow slits.