The campaign and its Web site, ThatsNotCool.com, encourage teenagers to set their own boundaries. It is intended to appeal to all teenagers, not just those with serious problems. “The kids don’t want to be told what’s right and what’s wrong,” Mr. Law said. On the site, teenagers can send one of 35 “callout cards” — brightly colored messages they can send by e-mail, post to their Facebook or MySpace accounts or download — that are meant to tell someone they have crossed a line. The messages are sharp. For example: “Congrats! With that last text, you’ve achieved stalker status.”