It's an extremely rare thing (as in I can't think of one off the top of my head) to hear about a credible terrorist threat being foiled by FBI work.
Maybe I don't understand anti-terrorism... but why trot out these phony stings and make the public think that these are just a bunch of incompetent over-hyped organizations (and I mean terrorist and intelligence alike)? If we are supposed to be suspicious and wary, wouldn't it be beneficial to have something really scary to feed the public?
But I've said all I'm going to say on that.
Business plan of every major religion.
I would probably attribute it to agents wanting to further their careers by catching some people and getting them convicted. All of the agent's office buddies are going after copyright violators, so they do too.
I agree that it may also be about agents who want to further their careers - because the punishments for copyright violation are so high, it probably looks just as good on the CV as a successful DDOS or spam case, and it's probably markedly easier.
That is a more severe and pernicious problem than most people realize.
Unfortunately I doubt that the USA is sufficiently democratic for that to work. So a better solution would be to write software that makes it a lot harder for governments to know what people are communicating on the internet.
The problem is that the government wields sufficient power that it's (very) cost effective for those who have sufficiently deep pockets (corporations, unions, other special interests) to woo the legislators for special privileges and rent seeking.
On the other hand, while voters collectively could wield power to counter this, it's diffuse, and any one particular voter has approximately zero influence, and thus has little incentive to make the significant investment in educating himself about what's going on. Thus, the electorate is generally ignorant (and rationally so), and does not know about (most of) the shenanigans going on with their government.
I think the real issue is democracy, no matter how well executed, really just isn't that good at protecting citizens from tyranny. Laws that ensure freedom and privacy are all good and fine, but they will never compete with math that ensures privacy and freedom.
Even were we to devise the perfect system of governance, advancement in technology to ensure the situation would still be essential.