I've been expecting this kind of stuff for years as well. I assumed, after witnessing how just two snipers essentially paralyzed an entire city, that the Islamists would get ideas. Just imagine three or four small teams like this operating simultaneously in every major US city. The entire country would grind to a halt.
“You cannot invade the mainland United States. There would be a rifle behind every blade of grass.” ~ Fleet Admiral General Isoroku Yamamoto, Commander-in-Chief of the Imperial Japanese Navy