That night, in March of this year, Jennifer tried to report the account to Instagram’s privacy-and-safety center, hoping it would get taken down. She asked several friends to fill out the “report violations” page too, but after a few hours, the account was still up. (Instagram’s help center recommends contacting local authorities in cases of serious abuse.) She considered calling 911, but this didn’t seem like that kind of emergency. So she waited until first thing the next morning and called a local deputy sheriff who serves as the school resource officer, and he passed the message on to his superior, Major Donald Lowe. Over the years, Lowe had gotten calls from irate parents whose daughters’ naked pictures had popped up on cellphones, usually sent around by an angry boyfriend after a breakup. But he immediately realized that this was a problem of a different order. Investigation into the Instagram account quickly revealed two other, similar accounts with slightly different names. Between them, the accounts included about 100 pictures, many of girls from the local high school, Louisa County High, in central Virginia. Some shots he later described to me as merely “inappropriate,” meaning girls “scantily clad in a bra and panties, maybe in a suggestive pose.” But some “really got us”—high-school girls masturbating, and then one picture showing a girl having sex with three boys at once.