Answer:
Block them and bully them back. Ignore them and don't get your stuff leaked or they will blackmail you. Also report them it works. Or you can blackmail them. Don't share pictures online. Call 911 if its emergency. If you are a child snitch on them to the teachers. Sue them for harassments and stalking.
call 800-273-8255 if your thinking of Sucide . Don't Sucide , don't let them win.