John Oliver and HBO’s Last Week Tonight take on another important subject, this time patent trolls. These are outfits that buy up patents (often overly broad ones handed out too carelessly by the U.S. Patent and Trademark Office). Patent trolls as a rule don’t actually use the patents to make anything; their sole source of income is lawsuits, or rather the threat of lawsuits. Defending against patent lawsuits costs millions, so the target of a patent troll lawsuit will often save money by settling for hundreds of thousands, even if they have an excellent chance of winning at trial.

Eleven minutes likely to leave you entertained, informed, and severely enraged:

by