If you haven’t been watching HBO’s Last Week Tonight with John Oliver you’re really missing out. Oliver takes advantage of the weekly format to devote long segments to topics that don’t often get a hearing from other late night comedians, let alone the corporate news media — often with hilarious results.

Last night’s episode provided a perfect example as Oliver spent 17 minutes eviscerating the national disgrace that is the U.S. prison system. He touched on everything from our unfathomable incarceration rate to the ineptitude of Bureau of Prisons Director Charles Samuels to the horrific effects of prison privatization. Come for the cogent analysis of mandatory minimum sentencing laws; stay for the puppet sing-along breaking down overcrowding and racial profiling.

When you’ve finished watching, add your name to FDL’s petition to the Bureau of Prisons telling them not to renew Corrections Corporation of America’s contract for its for-profit immigrant prison in Youngstown, Ohio.