Where does the money go? If it goes into the general fund and gets to be large enough, then government programs become dependent on it. The funds start to dry up if people actually stop engaging in the behavior. Then the government starts running low on funds they were dependent on.

I've always thought that these kinds of "vice taxes" shouldn't go into the general fund. They should go toward things that are related to helping the cause. In this case, the funds could go into awareness programs, subsidies for healthy foods, etc.

You forgot </sarcasm>