[Skywalk]

Not if you're thinking strategically. Also, cells are not necessarily in communication with each other AND there have been major arrests in Lackawanna, Portland, and many locations overseas.

Who's to say there isn't a cell preparing another form of terrorism in Houston, just waiting for the endgame to play out in DC?

[AEMILIUS PAULUS]

Another element militating against terrorist activity is the lack of "splash" involved in sniping. Compare the impact of crashing the airplanes into the buildings with the recent spate of shootings. I am not saying terrorism is impossible in the current shootings just not too likely.

[mhking]

Who's to say there isn't a cell preparing another form of terrorism in Houston, just waiting for the endgame to play out in DC?

I've had the impression that each cell is operating autonomously; in which case, coordinating multiple cities simultaneously, while not out of the question, would be the exception rather than the rule.