It was like something out of a Cheech and Chong movie — one of the later, unfunny ones. In 2003, the Justice Department, which apparently had nothing better to do, hatched Operation Pipe Dreams, an undercover sting that resulted in the arrest and incarceration of Tommy Chong. His crime against the homeland? Shipping bongs made by his family-owned business. This slender, revealing documentary, a/k/a Tommy Chong, traces the government’s attempt to make an example out of the legendary stoner-comedian, but it is also a portrait of resilience: Chong does his time (nine months) and has the last laugh, emerging as a born-again activist-survivor of the culture wars.