Who is getting sued and for what? What kinds of defensive strategies can help defend Linux, GNU and related projects? Of particular interest to free software contributors, this talk also has plenty of big picture to make it interesting for free software activists and users. I'll go over how the US patent system got to where it is and why it is such a problem for software in particular. We'll talk about what's already been tried and what's currently being done to protect free operating systems. Have you ever wondered what's at stake, how much money is changing hands or who's at risk? Perhaps you'd like to learn more about prior art and how that works? If so, then this talk is for you.