Microsoft's co-founder Paul Allen has filed suit against nine companies over patent violations. Through his current firm, Interval Licensing LLC, Allen is suing Apple, Google, AOL, Facebook, ebay, Netflix, Office Depot, OfficeMax, Staples, Yahoo, and YouTube (which is a subsidiary of Google). The claims involve four separate patents, most of which cover integral parts of how the companies named do business. For example, one patent allows site suggestions for consumers based on things they're currently viewing, while another allows related articles to be delivered while reading news. All in all, it sounds like Allen's patents -- if they're indeed found to cover these technologies -- are seriously vast. The suit, which was filed today, does not name any specific amount of damages he is seeking. Allen, who is one of the richest people in the world with an estimated worth of over $13 billion, recently pledged to donate over half of his wealth to philanthropic causes after Microsoft co-founder Bill Gates called on the world's billionaires to do so.