Microsoft has been asking for royalties from all sorts of Linux vendors and Android vendors. They've claimed something like "200 patent families" apply to Android. Most companies have signed up, as far as we know. Kyocera has not os Microsoft is suing them for infringement of 6 specific patents. Now we know which they are. They each look obvious to me but apparently that's not the test that is used in the US. <http://www.theregister.co.uk/2015/03/09/microsoft_lobs_sueball_at_kyocera/> Apparently Microsoft make billions a year off these. US patents expire 20 years after filing date. The latest was filed in late 2004 so it runs for almost a decade longer.