Gigaom reports that Google has filed a lawsuit this week against Rockstar, the patent holding company jointly owned by Apple, Microsoft, BlackBerry, Sony, and Ericsson whose portfolio comes mostly from the corpse of bankrupt Canadian telecom giant Nortel. In October, Rockstar had sued Google and a variety of Android OEMs — Samsung, LG, and HTC included — alleging infringement on a number of those ex-Nortel patents, and Googles countersuit is geared directly at sliding the platform out of the consortiums aim. The filing stops just short of calling Rockstar an outright patent troll: Rockstar produces no products and practices no patents.