I've been following the news about all the Boston bombing lately and I can't but getting shocked about how many people were involved the Friday in the hunt for the boston bombers: Districts in lock down, national guardsmen armed to the teeth, police, helicopters... just for two men.

Take into account that I'm from Spain, and that although I do not really understand how the U.S. works (I don't even understand exactly what's the paper of the National Guard in defense), we have been dealing with terrorism since 40 years or so, and when something blew up the measures were way more light than what I saw these days (And yeah, the bad guys used to get caught too).

Was any kind of "standard response" to any kind of terrorist attack, did the police thought they were chasing a bigger group of terrorists, did the initial shootouts (I haven't read a lot about them, though) forced the use of massive force, was the deployment a force demonstration to show the people the government had the situation controlled..?