I've consulted with the FBI and worked with professionals who earned my respect. The ones I met were highly competent and big believers in the Bill of Rights and in the rule of law. However, organizations change, and even good organizations have bad apples - especially when going rogue is a leadership goal.
I play cards with LEO of all stripes. Down to earth types. However, I still suspect, especially some of the more "elite" special ops squads.