Maybe not in waves, but there are terrorists in our country or trying to get in. I have a close friend in counterterrorism here, can't say who or where he works (not CIA). He finds 2-3 a day all around the world (all of different levels obviously), tracks them, etc. He actually had a plan flying out of Frankfurt stopped before take-off as it had a known terrorist on it. Plane was stormed by comandos and the guy was taken into custody. The flight's destination was a US city (didn't tell me).