Struck a nerve is absolutely right. Recall J. Edgar Hoover's legendary secret files?

Hoover remained as Director of the FBI for 48 years because he had secret files on presidents and members of congress - nobody dared fire him or attack him. He had Martin Luther King, Jr.'s bedroom bugged. He documented Bobby Kennedy's meetings with Marilyn Monroe. He documented illegal abortions, adulterous affairs, homsexuality, drug usage and Mafia ties of members of congress and their families. Lyndon Johnson said of Hoover, "I'd rather have him inside the tent pissing out than outside the tent pissing in."

If Hoover, with the primitive technology available to him, was able to intimidate Presidents and members of Congress, one can only imagine the near total control the NSA has over those same office holders today.

"Hoover is the inventor of the modern American national security state. Every fingerprint file, every DNA record, every iris recorded through biometrics, every government dossier on every citizen and alien in this country owes its life to him. We live in his shadow, though he's been gone for 40 years. As they always told the agents at the FBI academy when they were training, 'An institution is the length and shadow of a man.' "
http://www.npr.org/2012/02/14/146862081/the-history-of-the-fbis-secret-enemies-list

The article I cite from below is an interview with author, Ronald Kessler about his book Secrets of the FBI. Here are Kessler's creds:

“He [Hoover] would send someone over on a very confidential basis,” Heim said. As an example, if the Metropolitan Police in Washington had picked up evidence of homosexuality, “he [Hoover] would have him say, ‘This activity is known by the Metropolitan Police Department and some of our informants, and it is in your best interests to know this.’ But nobody has ever claimed to have been blackmailed. You can deduce what you want from that.”