Your comment reminds me of a post I read on a popular police forum about J Edgar Hoover (the infamous Director of the FBI for half a century). He created a professionalized police / intelligence force, but he also abused the rights of many citizens and elected political officials with that force. Supposedly he even used it to blackmail some of the Congressmen who were legally obligated to oversee his department.

And the comments in that post were a Rorschach test of where the commenter fell on how "necessary" the abuses of the FBI were.