There are cases where people are too stupid to take care of themselves and I don't feel (much) sympathy for them. These are usually the situations where their own stupidity affects only themselves. Examples: smoking to some extent (open spaces, smoker's house), video game addiction, light drinking, light weed smoking, walking/driving/fishing on a frozen lake... However, I can think of plenty of situations where one's stupidity puts others at risk, at which point I'm for preventing them if possible from being stupid. Examples: heavy drinking (induces violence, and drunk driving if you drive), heavy weed smoking (it's just as bas as drunk driving if you drive) or heavy drugs (same, plus the addiction which is going to cause trouble), overspeeding in city areas (kids don't have the physical ability to see danger like adults do, and can't estimate speed nearly as fast), smoking near a gas pump...