YEARS AGO, WHEN I still had a social conscience, I volunteered for Books to Prisoners, a nonprofit that sends books to the big house. I opened letters from prisoners, read their requests, and tried to find them in our limited library. Most letters were simple supplications, except for one that haunts me still. Tidily typed, it was an impassioned plea from a kid who'd been arrested at a Dead show for selling marijuana. More than books, he wanted people on the outside to know that he still existed, and that even without a criminal record, he was serving the unfathomable sentence of 20 years.

Grass, a documentary by Ron Mann, illustrates our government's continuing "War on Drugs"--a failed experiment that has cost this country hundreds of billions of dollars and landed that poor harmless hippie, and many thousands more like him, into the slammer for inhaling a plant that makes you giggle and eat Cherry Garcia® ice cream.

Narrated with just the right stoner sound by loony Woody Harrelson, the film uses stock footage, a rousing soundtrack, and tasty graphics to carefully illuminate the hidden history behind this harmless plant. Much of the stock footage is unintentionally hilarious à la Reefer Madness, such as Ronald Reagan intoning that marijuana causes memory loss, or an uptight cop claiming, "The tea addict is a very sick guy," while puffing on his Lucky Strikes. But Mann wants us to look past the easy laughs. One startling sequence shows a terrified young man hauled off in handcuffs for selling two joints to an undercover cop. His weeping parents hold up his many medals: "We were just so proud of him over there and so relieved he came home alive." Newly returned from two tours serving in Vietnam, he got 50 years.

I couldn't help but wonder--was he still inside? And what about the hippie whose letter I'd answered so long ago? Were they both still suffering in prison for nothing? To its great credit, Grass won't let us take a big bong hit and forget them. It demands that we not only remember, but use our votes to save others from their fate.