As someone who lived in Cancun for over five years, I can say it is reasonably safe for teens on their grad trips. As for drug violence among cartels, this is happening mostly in the northern border towns, such as Laredo and Ciudad Juarez. What your teen must remember is to stay with a group and DO NOT leave your friends, as petty crimes such as theft do occur, as well as horrific crimes such as sexual assault. Remember there are safety in numbers. High levels of intoxication do take place among visiting teens, so I would not advise underage drinking. I have seen young adults so inebriated, they lose all their cash, travellers cheques and in some cases are the prime targets for rapes and assaults. I have even watched as a girl passed out on the street with no friends in sight to help her. She was very lucky that I happened to be strolling by from a nearby club and I woke her up and helped her back to her hotel. Who knows what could have happened to her had I not walked by! Alcohol poisoning is also rampant as liquor flows freely. Parents, know your teens. Alcohol and drugs is the worry and your teens actions, not CANCUN. If you believe they would not use their best judgements and become easily influenced by these toxins, they should not go to Cancun. Remember, poor Natalie Holloway went missing when she went off with strangers. Trust KNOWONE, stick with your group and all should be fine. Crimes against visitors are often left unsolved by the local authorities. In closing, Cancun is always busy and bustling in the hotel zone, so clubbing is usually a fun and exciting experience. Happy travels !