In a detailed court motion filed Monday as part of an ongoing lawsuit against the NSA, ACLU says program has 'chilling effect'

The National Security Agency's mass tracking and collection of Americans' phone call data violates the constitution, has a chilling effect on first amendment rights and should be halted, accord to a court motion filed by the American Civil Liberties Union on Monday.

In a detailed, legal critique of the NSA programme, the ACLU warned that such long-term surveillance "permits the government to assemble a richly detailed profile of every person living in the United States and to draw a comprehensive map of their associations with one another."

The motion is part of a lawsuit filed by the ACLU in June, one of several against the NSA following the Guardian's disclosures via whistleblower Edward Snowden, of the agency's mass surveillance of US citizens. Documents from Snowden revealed a secret Foreign Intelligence Surveillance Court order directing Verizon to give the NSA all call detail records or "metadata" relating to every domestic and international call for three months, in a court direction that is renewed on an ongoing basis.

It "allows surveillance that is essentially indefinite", the motion says.

The ACLU document is peppered with quotes from literary, academic and other sources, to illustrate the danger of mass surveillance by the government, including the writings of George Orwell and The Lives of Others, an award-winning movie about the monitoring of East Berlin by the Stazi by director Florian Henckel von Donnersmarck.

In statements after the programme was disclosed, intelligence and government officials have stressed that the NSA does not collect the contents of US calls, only the "metadata", such as the numbers called, the duration and timing of the calls. The information, they say, can only be interrogated if they suspect terrorism.

The legal motion argues that the NSA programme, which the agency says is used for counter-terrorism, has overstepped its bounds. Quoting Representative Jim Sensenbrenner, Republican of Wisconsin, the author of the Patriot Act in 2001, it says the NSA has "scoop[ed] up the entire ocean to . . . catch a fish."

The motion says: "The chilling effect of the mass call-tracking program is apparent: any person hoping to approach plaintiffs with proof of official misconduct would be understandably wary knowing that the government receives, almost in real-time, a record of every telephone call."

The ACLU's clients include prospective whistleblowers seeking legal counsel, and "government employees fearing reprisals for their political views". Phone calls, even the mere fact that a call was made, from such clients are "particularly sensitive or confidential", it said.

A declaration in support of the motion by Edward Felten, a professor of computer science and public affairs at Princeton, warns that "even basic inspection" of the metadata on the calls made in the US each day allows the government to pry into the population's most intimate secrets. They include, Felten wrote, the "rise and fall of intimate relationships" the diagnosis of a life-threatening disease or the identity of a prospective government whistleblower.

It can reveal, Felten wrote, "when we are awake and asleep; our religion, if a person regularly makes no calls on the Sabbath, or makes a large number of calls on Christmas Day; our work habits and our social aptitude; the number of friends we have; and even our civil and political affiliations".

Calls to certain helplines, or support groups, for instance sexual assault, domestic violence or abortion clinics are all tracked by the NSA, the motion says.

The NSA's mass collection of phone metadata was approved by the Fisa Court but the ACLU says that part of the basis for the court's approval, a Supreme Court ruling called Smith vs Maryland 1979, involved narrow surveillance directed at a specific criminal suspect over a limited time period.

It argues that nothing in Smith "remotely suggests that the constitution allows the government's mass collection of sensitive information about every single phone call made or received by residents of the United States over a period of seven years."

It says that the Supreme Court has "repeatedly recognised" that the government's surveillance and investigatory activities can infringe on associational rights protected by the first amendment.

The ACLU's lawsuit, filed on 11 June 2013, names James Clapper, the director of intelligence; Keith Alexander, the NSA director; Chuck Hagel, the defence secretary; Eric Holder; the attorney general and Robert Mueller, director of the Federal Bureau of Investigation. It says that the NSA's ongoing tracking of their phone calls exceeds statutory authority and violates the first and fourth amendments.