Yep. We have DHS. And we hear almost nothing about successes.
FBI, DHS, NSA, if any of them uncover some plot to nuke half the country and stop it 4 seconds before the countdown timer with Jack Bauer leading the charge, we barely hear about it.
They do this because, well, if we knew how many times our asses were saved in the background, then "the people" would freak out. Two, tangos would analyze the failures of others and learn. Three, classified.
Public impression is that the government is "trying" but not good at stopping bad guys. Reality is that anyone with half a brain and a few followers could bring this country to its knees, but they don't, because stuff is happening that we don't see.