It considers itself above the law to the point of being able to kill Americans without trial.
That aside, 40 years ago the NSA stated that it was above the law because it was created by Executive decree and tus not bound by statutory law:
"NSA does not have a statutory charter; its operational responsibilities are set forth exclusively in executive directives first issued in the 1950s. One of the questions which the Senate asked the Committee to consider was the "need for specific legislative authority to govern the operations of...the National Security Agency."
According to NSA's General Counsel, no existing statutes control, limit, or define the signals intelligence activities of NSA. Further, the General Counsel asserts that the Fourth Amendment does not apply to NSA's interception of Americans' international communications for foreign intelligence purposes." [1]
[1] Church Committee Report on NSA Surveillance Affecting Americans (1975)