First of all, I want to express my condolences to the friends/family of Stephanie Yau. My friends and I have been attending raves for more than six years each, and none of us has ever seen or heard of rohypnol "the date rape drug" being used. I have been a security guard at many parties here in State College. In almost of the cases where I've worked, we have at least 4-5 security guards at a venue for about 125 people. We even invite EMT's (Emergency Medical Technicians) for extra safety.
We sometimes employ video cameras for surveillance. We pat people down extra hard, feeling inside shoes, opening bags, purses, wallets. I, personally, have seen all of the contents of every girl's bag that passed through the door.
We employ a friendly but firm attitude to all of our customers. Customers found with drugs are not allowed to enter the facility. Here in State College, we employ more security measures than some clubs in Pittsburgh (where people just walk in with bags, many times) and Philadelphia. We have even utilized metal detectors, to prevent weapons.
If someone really wants to bring in drugs, they will find a way, like in any given situation. Drugs are inevitably present at almost any music event. My mom was at a concert this summer where people were taking mushrooms and smoking weed. Hey, closed-minded conservative State College residents, let's protest the next rock concert, because middle-aged women might be getting high.