The ruling, in a case brought by the American Civil Liberties Union, also held a broad gag provision of the Act to be an "unconstitutional prior restraint" on free speech. It is the first ruling to strike down any of the vast new surveillance powers authorised by the Patriot Act.
The Patriot Act was drafted in the weeks following the September 11th atrocities in order to boost the fight against terrorism. It has been widely criticised for undermining civil liberties in the US, and has been subjected to several legal challenges. One of these related to the issuing of what are known as "National Security Letters" (NSLs).
Prior to the Act the FBI was entitled to issue, without court approval, NSLs that required ISPs and other communication providers to provide sensitive customer records on suspected terrorists and spies. Since the Act came into force, however, the FBI has been able to issue NSLs to obtain, according to ACLU, information about anyone at all.
The civil liberties group argued that the provision was worded so broadly that it could effectively be used to obtain the names of customers of web sites such Amazon.com or Ebay, or a political organisation's membership list, or even the names of sources that a journalist has contacted by e-mail.
The Act also required those receiving an NSL to keep quiet about it.
The American Civil Liberties Union, the New York Civil Liberties Union and an unidentified ISP brought a challenge to the law earlier this year, and were forced to file the suit under seal to avoid penalties for violating the NSL statute's broad gag provision.
But yesterday Judge Victor Marrero of the Southern District of New York struck down the NSL provision on the grounds that it violates free speech rights under the First Amendment as well as the right to be free from unreasonable searches under the Fourth Amendment.
"Democracy abhors undue secrecy," said the Judge, who also struck down the gag provision of the Act. "Under the mantle of secrecy, the self-preservation that ordinarily impels our government to censorship and secrecy may potentially be turned on ourselves as a weapon of self-destruction."
The ruling, which has been stayed for 90 days in order that the Justice Department may appeal, bars the government from issuing National Security Letters or from enforcing the gag provision.
The American Civil Liberties Union and the New York Civil Liberties Union hailed the ruling as a blow to the current administration's efforts to expand government surveillance powers.
"Today's ruling is a wholesale refutation of excessive government secrecy and unchecked executive power," said ACLU attorney Jameel Jaffer. "As this decision suggests, certain provisions of the Patriot Act should never have been enacted in the first place."
"After labouring under a gag provision for months, it is an enormous relief to be able to tell the world just how dangerous and extreme this Patriot Act power is," said ACLU Associate Legal Director Ann Beeson. "As the judge recognised, the Patriot Act imposed a 'categorical, perpetual and automatic' gag on every person who received a National Security Letter, as well as their lawyers."
According to Reuters, the US Attorney General, John Ashcroft, confirmed today that the Justice Department is likely to appeal the ruling.