@Ebbie

"Had he/they successfully killed crowds of people while on the run, would you still have laughed?"

No Ebbie I wouldn't. The phrase I used was one to express disbelief, not a literal description of my potential reaction.

To take the jist of your comment above to its logical conclusion if we all stay in doors 24/7 no one can be an open terrorist target. Generally speaking the aim or terrorism is to terrify by means of violence and the threat of violence.

If the UK government had made the population of Belfast stay in doors and shut their businesses and public transportation links because of serious and impending known terrorist activity; the streets would have been empty for decades. If someone gave the enemies of the US a choice between a handful of civilian dead or the crippling of the US economy and personal freedom of its citizens by causing citywide shutdowns which one do you think they would choose?

Do you think that Islamist Terrorists overseas post videos of the beheading of construction, oil and aid workers to kill individuals; or to frighten other constuction, oil and aid workers into staying at home and not working where the terrorists don't want their expertise or humanity?

For those who died and were injured and their families it is an unimaginable personal tragedy that no one should have to suffer. For the terrorists the shut down of an entire city was (IMO) the bigger "victory" in terms of anti-US sentiment and goals.

Having served with US troops overseas I don't think it is part of the DNA of US citizens to respond to threat by hiding and clearing the streets. And I don't think that US citizens would tolerate a repeat of another curtailment of their freedom of movement under such circumstances. Let's not forget that when the "shutdown" was lifted the threat was exactly the same as when it was initailly enforced. The powers that be (IMO) just realised it was an unsustainable overreaction and lifted it.