The National Security Agency, the top-secret spy shop that has been secretly eavesdropping on Americans under a plan authorized by President Bush four years ago, destroyed the names of thousands of Americans and US companies it collected on its own volition following 9/11, because the agency feared it would be taken to task by lawmakers for conducting unlawful surveillance on United States citizens without authorization from a court.

http://www.truthout.org/docs_2006/010506I.shtml