November 23, 2011 10:10 am Signs that a Teen is Abusing Drugs Teens will experiment but how do you know if the substance use becomes a serious problem, and where do you go for help? US & World Videos 18:12 Police begin to clear protesters from USC campus 2:34 Campus police union blames UCLA for violent response 3:18 USC's commencement preparation includes increased security patrol 1:56 1 person killed after car crashes into South LA church 3:30 Protest on USC campus continues ahead of graduation