I'm having no luck finding a breezy book to try and match Becky's entries. OK, you win, it can't be done (No, I might be able to find a breezy book, but Becky has the patent on funny write-ups). So.... let's all read about J. Edgar Hoover and those zany guys at the FBI!
This is one heck of a story. Starts back with presidents from Lincoln on using private investigators to try and figure out what's going on inside the country and Teddy Roosevelt setting up a federal agency for the same purpose. They didn't bother with pesky things like a congressional charter (there still isn't one for the FBI) or too much oversight, because what they wanted to know normally couldn't be done with search warrants and lots of rules. This book really isn't about J. Edgar being a loose cannon. It's about every president wanting the kind of information those agencies (the FBI is only the most recent incarnation) could provide and J. Edgar doing a pretty good job of providing it.
When Nixon came on the scene, he was so far out on the paranoid edge as far as wanting info on everyone that even Hoover pulled back from him and Nixon created his own very poor spy organization (the Plumbers) with disastrous results. The fallout from Watergate hamstrung the agency, which is only now in a position to where rules exist to guide the FBI yet give them enough leeway to do the job. I got to the end of the book with hope that there can now be a balanced future between competent outcomes and infringement of personal liberties.
The is a real page-turner. There have been continuous instances of internal and external terrorists in the U.S. since the 19th century and this narrative puts them into context and actually changed some of my thinking on individual freedom vs. civic safety. The book does not focus on the federal law enforcement aspect of the agency but on intelligence gathering and how it has sometimes kept us safe and sometimes missed the boat. It's a great read and a wonderful historical perspective.