A group of boys around school freeing the fields of injustice and crime. They achieve this by literally beating the shit out of innocent people, terrorising the school population into obedience. They often attack using the "Gangfuck" method, in which they circle the lone victim, wrestle him to the floor, and kick the shit out of.
Often suspended from school for 'GBH' and assault. A Justice League has no clear leader, just a lust for violence and fear.
Billbo-"Holy shit did you see that guy left on floor covered in blood?"
David-"Oh shit the Justice League are back in school"