Need another reason to keep your teen away from the social media scene? Enter the latest form of cyber bulling. In the disheartening online trend dubbed "teen shaming," users nab photos of other users and alter them meme-style, adding insulting captions and unwanted advice. The practice isn't just hurtful -- in some cases, it might even be illegal. "Everyone thinks they can do anything they feel like doing online. They can't," Internet privacy security lawyer Parry Aftab told ABC News. "Free speech has its limits. If you defame somebody and you harass somebody, if you target them -- that may be against the law."