I saw a show a couple of years ago about this. Apparently, there is a concern with modern milking techniques. The cow's udders can become infected, so the farmer puts an antibiotic on the udders and the pus and antibiotic gets into the milk. That and growth hormones in the food for the cows adds up to this kind of warning. It was a bit extremist in that the expert went on to say that no human should ever drink cow's milk.
My wife is Russian and only drank raw milk there. She can't stand our pasteurized milk and cheese. Not so much from being scared, but I now use either soy or rice milk. It's more a high cholesterol thing than anything for me. I probably drank a half gallon of milk a day when growing up. If I had kids, I would probably do more research to help make up my mind.