It's possible that you won't even know -- studies show that only 5 percent of middle-schoolers tell their parents when they're the victims of cyberbullying (a disturbing statistic, if we ever saw one). Watch for these clues that something's going on in your child's online world, then get involved:
1. Social withdrawal
Your tween stops playing games online or using the phone, and her comrades are mysteriously MIA. "Most online attacks are launched by friends who know their passwords... and their secrets," says cyber lawyer Parry Aftab, founder of Stopcyberbullying.org.
2. Fear of technology
Your child spends her evenings catching up on her reading (not that that's a bad thing) instead of logging on, and appears nervous when text messages pop up.
3. Bad behavior
"Younger kids will misbehave when they're tired, but when tweens act out, there's a good chance it's because someone is making their life miserable," says Monica Vila of Theonlinemom.com.
4. Ask around
Odds are your 12-year-old told her best pal about the cruel comments made about her weight in a chat room, then she told her mom. Check in with parents you trust.
5. See for yourself
If all else fails, Internet parental controls and monitoring software -- as well as regular, honest chats about your kid's online life -- can help you identify an elusive bully.