Not a problem. But you forfeit the right to complain if a bomb goes off in the subway.
No you don't. You complain all you want about the bastard that brought it in. Same of they just blew itup on a street corner.
Not being invaded doesn't nullify the right to complain if someoene does something stupid.
Maybe we should make it illegal for anyone to leave their house. After all, if you leave your house, and something happens, you can't complain.