You have no idea how often it happens. Drugs are readily available. It's not unusual for someone to spike a girl's drink when she is not looking. A smart girl keeps her hand over the top of her glass. Even if she is drinking ginger ale. Many times that's what she is drinking.
Those of you who think it isn't happening are projecting your own values onto todays college students.
Men have been spiking drinks since the dawn of time. In my day, it was LSD. That’s why you don’t drink heavily at parties and you hold on to your glass - particularly if you are partying with strangers. If you know that - and I know that - why don’t these girls know that? Where are their parents with the good advice?