The International Trade Commission has ruled that Microsoft did not infringe upon any Motorola Mobility patents with the Xbox 360. The decision represents the end of an investigation that stretches back to 2010. Motorola Mobility contended that Microsoft had infringed upon several of its patents with the device, which led to the ITC issuing a preliminary ruling in April of last year that sided with Motorola on four different patents.

However, in the legal back-and-forth all but one of the patents had since been chipped away — some found to be invalid, while Motorola itself requesting others be pulled from the proceedings. In March an ITC administrative law judge ruled that the asserted claims of the one remaining patent had actually not been infringed after all. Today's ruling by the ITC Commission affirms that decision.

It's a clear, decisive win for Microsoft — and just one more blow to Google-owned Motorola's patent warfare ambitions. A judge in another case ruled just last month that Motorola's patents were worth nowhere near what the company has sought in various legal battles. With the patent portfolio turning out to be a bust and no spectacular hardware yet on the market, it leads one to wonder just why Google bought Motorola in the first place.