The OP is spot on about the spying.
But I really dont think, well I know not all LE is corrupt. I think there a lot of patriots in the FBI and I know for a fact that there are in the PD's (excluding a few very large city's) I would bet that most rural LE is bordering on 99% patriotic not 100%.
CIA, who knows.
Congress and Senate, well they can all fuck off in my opinion. We may have 10 out of 535 that are worth keeping.
The bottom line is that the top dogs are ruling the roost and LE wants to keep their job just as much as you and me.
At some point though the shit is going to hit the fan. My feeling is that it may be very soon.

Your right though. Always clean from the top down. But that brings me to another point, who has the balls to do the cleaning, to prosecute and convict.