Help my friends meeting some guy she met over the internet??!?

this is very serious... unfortunately you can't stop your Friend io would recommend telling somebody who DOSE have her parents number your friend might not like it but you can't let her have sex with a 17 year old if she is 13 he is probably a paedophile why else would he be doing this when he could do it with someone his own age. it is also illegal and could get your friend and the 17b year old arrested.