[JURIST] The American Civil Liberties Union [advocacy website] announced Thursday that it, along with an unnamed library, has filed suit [press release] in the US District Court of Connecticut against US Attorney General Alberto Gonzales and FBI Director Robert Mueller challenging the constitutionality of a provision of the USA PATRIOT Act [PDF text]. According to the complaint [PDF text], the ACLU is challenging the government's use of an administrative subpoena known as a National Security Letter, which allows the FBI access to library records and prevents anyone in receipt of the subpoena from ever stating that the FBI made the demand. The current suit is under a heavy gag order, which the unnamed library and ACLU have challenged on First Amendment grounds. The court has scheduled an emergency hearing for August 31 to hear the request. Reuters has more.