my thoughts too, Stuxnet but for GPS satellites. Too much of a threat to the US GPS system? Maybe a target for Russia but unlikely because they have no competing system. The only thing that leads away from it being US orchestrated is that they found Stuxnet, so if they found this you could be pretty sure that US/EU relations would be very shaky. Of course perhaps then Russia make it look like a US attack to divide a wedge between allies.