UFO? Strange Aircraft Over Boston Area; FAA Not Talking

Is it just a coincidence that something like this is happening on the heals of the Boston Marathon Massacre?  In the days following the arrest of the Islamist terror suspect Dzhokhar Tsarnaev, three more arrests were made.  Officials have given mixed signals on additional suspects, although in recent weeks they've acknowledged they believe Tsarnaev brothers had help from Russia, as well as the United States.  So what's with this strange aircraft in the sky's over the Boston suburb of Quincy?  Is it tied to the bombings?  Are they on the hunt for more terrorists?  Is it something else?  And is this happening elsewhere?