BOISE, Idaho (AP) — Rylee Driscoll was a student at Rocky Mountain High School in Meridian when fellow students began harassing her online.

It started with an old-fashioned rumor that she was "the rudest person ever." The criticism quickly blew up on Twitter. Classmates started sharing messages accusing her of theft. Going to school became so hard that she started skipping class.

She heard the advice from parents and teachers to ignore the comments and turn off the messages. She couldn't do it.

"I know I shouldn't have responded," said Driscoll, who graduated last year. "I just got so mad, and...