The suit comes after Times reporter Charlie Savage filed several Freedom of Information requests [ http://www.lawfareblog.com/wp-content/uploads/2011/10/Secret-law-FOIA-complaint.pdf ] for a classified report about the government's authority to collect intelligence under the PATRIOT Act, and was refused. He made the requests after two senators charged that Americans would be deeply disturbed by the government's use of the law.
The section of the act in question allows the government to order the production of "any tangible things” on “reasonable grounds" related to an international terrorism or counterintelligence investigation. The lawsuit demands the release of at least a redacted version of the report to explain what that allows.