I've become a bit of an Everything is Terrible addict of late. Their latest artifact is one of the few items they have posted that I have a clear memory of watching on TV:
The reason I remember this commercial so well is because it's one of the most insulting things I've ever watched. Even as a teenager, I saw how ridiculous this argument was. You can replace the joint with a bottle of vodka and it doesn't change a damn thing. There are very few problems with drunk doctors or cops because there are clear reprocussions for such violations of their positions. Apparently, the folks that made this commercial either figured that these would mysteriously not apply to pot smokers if it were legal or that viewers were dumb enough not to think of this counter argument. As I said: Insulting.
And, by the way, if you want to do a serious scare commerical, then don't get the same goofy voice-over guy who did all those game and toy commercials back in the day. It kinda muddles your already crappy message.