Why do people give girl's purple nurples?

i am 14 and i am a freshmen in highschool. im a girl. i have recieved so many t!tty twisters, uhmm esspeccially nipple cripples. they hurt....esspecially on girls nipples. i have been through alot in highschool. i have had my bra ripped off. a guys hand up my bra, for one, innapropriate. the whole 9th grade has seen my nipples and breasts, kinda sucks, right?