Just try to phase out this blindly fearing and being paranoid of the public safety reaction.. To someone blowing up a couple hundred folks in arguably one of the hardest countries to pull off such an operation. I'm mostly worried that it was pulled off in the first place, not that the government is actually trying to do something proactive to halt the still-on-the-loose bomber(s).
First: NO ONE BUT YOU HAS SAID JACK SHIT ABOUT THE GOVERNMENTS ATTEMPTS TO FIND THE BOMBER. No one has fucking complained about that! YOU were the one who started getting pre-emptively pissy about the fact that people might.
People have expressed worry about the historically likely possibility that politicians are going to use this an opportunity to consolidate their power, as a political tool. Which is a pretty damned different thing from a heightened state of alert while a known criminal is on the loose who obviously likes blowing people up.
As to your worry that someone was able to pull this off in the first place (and your laughable statement that this is difficult in the US):
It's much harder to pull this off in many other countries that have this happen FAR more regularly. It was a hell of a lot harder to pull off bombings like this in North Ireland some years back, and yet it happened all the time. Do you know why?
Because it's this simple: Stopping stuff like this is much, much harder than doing stuff like this. If enough people want to do stuff like this, you can't stop it. You just can't. The only real protection is people not wanting to kill you; living in a society where it's seen as unacceptable and the vast majority of people believe that. It's like murderers: If someone halfway capable really, really wants to kill you, they're probably going to. (Unless you're incredibly wealthy and well protected, and even that isn't usually enough to keep you alive)
The US has been blessed not by any amount of spectacular security, but by the simple fact that
most people in our country do not want to blow other people up. This is our first, and most effective safeguard, protection, and security against stuff like this. The fact that people do not generally want to murder other people is the fact that holds our society together. If even 1% of people tomorrow wanted to set off a bomb, that's it - we're done. There's no stopping it from happening. Lots of people are going to get blown up. Even our security, what of it is effective, tends to be geared around this - making it unappealing to take this action.
Are there real security improvements we could make, that would either make this less desirable as an action or raise the competency requirements of the planners (thus reducing number of successes)? Maybe! Note that most people have gone out of their way to say they hope that if changes are made, they hope those changes to be reasonable and effective. Those aren't the sort of changes people here would have a problem with.
Unfortunately, those aren't the sort of changes people overcome by fear tend to want. They want big. They want showy. They don't want safety - they want a security blanket, something they can cling to to assuage their fear, something they can use to cover their eyes and pretend everything is going to be alright THIS time, while the real problems go unaddressed. And we have a country run by politicians who are all too happy to give that to people in lieue of real solutions, and who have shown time and time again that they see events like these as an
opportunity.
I think Boston is handling this well so far, truth to be told. The people of Boston are not acting afraid. The politicians and the police are NOT cultivating fear. They are engaging in a bit of action meant primarily to reassure people, but even that seems to have a reasonable amount of desire for effectiveness behind it. It gives me hope that at least for the foreseeable future, the response will be a good one, and that people will fight through this, find the guy responsible, sentence him for his crimes, and move on after helping each other back to their feet.
I just hope that those who see something like this as an opportunity to make you afraid don't get to use it as such.