The NSA has spied on members of Congress, but acknowledging that would unnerve millions of Americans. That's why their official response to the letter was so evasive that CNN summed it up, "NSA won't say whether it spies on Congress." The NSA noted "procedures that protect the privacy of U.S. persons," and said that "members of Congress have the same privacy protections as all U.S. persons." Put differently, a program that collects data about virtually every phone call in America cannot help but include the phone numbers that members of Congress dial, as well as the numbers of those who telephone members of Congress.
http://www.theatlantic.com/politics/archive/2014/01/the-danger-of-nsa-spying-on-members-of-congress/282827/