This was one of my very first thoughts, considering the timing of the events and the implementation of Verizon's 4G. However, the locations don't seem to coincide with the areas of the country where they are actively using a 4G signal...or at least where they are reporting it. Further investigation is needed in reference to the other carriers.

Then again, while most of the incidents seemed to have happened here in the U.S., these events do seem to extend well beyond our borders and are more of a global event...