But the people who spread these ideas usually can't prove them. 

As the years pass, however, secrets surface. Government documents become declassified. We now have evidence of certain elaborate government schemes right here in the U.S. of A.

The 18th Amendment, which took effect in January 1920, banned the manufacture, sale, and transportation of alcohol — but not consumption. Despite the government's efforts, alcoholism actually skyrocketed during the era.