I agree with you about obesity. But what's the solution, prohibiting snack foods? Governmental control over what people eat?

I disagree entirely with regard to responsible use of heroin and cocaine; a large percentage of people who have ever tried those drugs do not go on to become addicts and only try them or use them occasionally. That perception of danger is largely created by the anti-drug crowd, and by severe addicts.

Zinberg eventually interviewed 61 controlled opiate users. His criteria excluded both dabblers (the largest group of people who have used heroin) and daily users. One subject was a 41-year-old carpenter who had used heroin on weekends for a decade. Married 16 years, he lived with his wife and three children in a middle-class suburb. Another was a 27-year-old college student studying special education. He had used heroin two or three times a month for three years, then once a week for a year. The controlled users said they liked "the 'rush' (glow or warmth), the sense of distance from their problems, and the tranquilizing powers of the drug." Opiate use was generally seen as a social activity, and it was often combined with other forms of recreation. Summing up the lessons he learned from his research, Zinberg emphasized the importance of self-imposed rules dictating when, where, and with whom the drug would be used. More broadly, he concluded that "set and setting" -- expectations and environment -- play crucial roles in shaping a drug user's experience. link

Cocaine is in a class by itself...millions of people use it in powder form as a party drug and never become addicted.