Pot smokers.

[Brian37]

One lung, working at ~50% efficiency, is a good motivator to not smoke anything.

I am not going to lie, I smoke cigarettes. But my argument isn't about destroying one's own health. My argument with any drug, is against the morons who want to project their risk taking on others. I hate the idiots who drink and drive and smoke pot and drive. It isn't the drinking or smoking by itself, but the assholes who put other's lives at risk thinking nothing bad will ever happen.

I have been a passenger in cars with both drunk people and pot smokers, and believe me, they fool themselves. 

Plenty of times when I wanted to meet friends at a bar, I tell them I would take a cab. I always hated it when they got annoyed when I wanted to take a cab home. I asked them if they were going to drink, they'd say yes, then get annoyed that I was going to take a cab home. 

Pot should be legal, but it should be treated like any drug and driving.