Ordering Valium over the Internet?

I’ve been looking at them forever and not really thinking about them, but what about those websites you see that come up offering drugs like valium “online for sale without a prescription”? I suppose I also never asked such a question, but having or buying prescription drugs without a doctor writing out the slip for you… is that illegal?

What are the chances that these online companies are selling you sugar pills instead of the actual ingredients? If it’s the real deal, and if selling prescription drugs online is illegal, how do these companies get away with it?