Nine girls, all 13 to 15 years old, were arrested for gang activity Wednesday morning at their Fayette County schools, according to the Atlanta Journal Constitution. The girls were turned in by other students who reported to school officials that the girls were making threats and wearing pink and black clothes. Peachtree City police were already tracking the girls for allegations of bullying, beating in new gang members, carrying weapons and apparently sharing information on Facebook. Investigators are increasingly monitoring social media websites to track gang activity, as we reported last month. Surveys across the country also show a nationwide trend of girls getting arrested more often than boys.