Paul Allen, the billionaire who co-founded Microsoft with Bill Gates, is taking eleven companies to court. On Friday, Allen sued Apple, Google, AOL, eBay, Facebook, Netflix, Office Depot, Office Max, Staples, Yahoo, and YouTube. His beef? Allen says the Silicon Valley behemoths are freely using patented technology he developed at his Palo Alto laboratory. Since leaving Microsoft in 1983, Allen has bought a professional sports team and created a museum for rock and roll. According to The Wall Street Journal, patent litigation like Allen’s suit is becoming increasingly frequent.