A woman uses a smart phone to photograph a young man holding a shotgun at an exhibit booth at the George R. Brown convention center, the site for the National Rifle Association's (NRA) annual meeting in Houston, Texas

NEW YORK (Reuters) – The National Rifle Association said on Wednesday it supports a lawsuit brought by civil rights groups to strike down the U.S. government’s broad telephone surveillance program, citing potential violations of gun owners’ privacy rights.

In a brief backing the American Civil Liberties Union’s lawsuit against senior U.S. government officials, the NRA said the collection of vast communications threatens privacy and could allow the government to create a registry of gun owners.

Civil rights groups filed the lawsuit earlier this year after documents leaked by former National Security Agency contractor Edward Snowden revealed a massive government program to collect and store phone and Internet records from major telecommunications companies.

The surveillance potentially provides “the government not only with the means of identifying members and others who communicate with the NRA,” the brief said, “but also with the means of identifying gun owners without their knowledge or consent.”

The NSA referred questions to the U.S. Justice Department, which declined to comment.

U.S. National Intelligence Director James Clapper declassified some details of the program, acknowledging it existed, after news stories from Snowden’s leaks appeared in the Guardian of Britain and the Washington Post.

The ACLU said it welcomed the support from the NRA in its suit against Clapper and other officials filed in U.S. District Court for the Southern District of New York.

“Americans from across the political spectrum value individual privacy,” said Jameel Jaffer, one of the ACLU lawyers on the suit. “The philosophical roots may differ, but I think that is a widely shared American value.”

Jaffer also pointed to another supportive brief filed on Wednesday by Representative James Sensenbrenner of Wisconsin, one of the authors of the 2001 Patriot Act that has been cited as part of the rationale behind the NSA’s program.

“The defendants attempt to justify their practice of collecting the records of every telephone call made to or from the United States, including purely domestic calls, by claiming that Congress intended to authorize precisely such a program,” said Sensenbrenner’s brief. “But Congress intended no such thing.”

President Barack Obama has defended the sweeping government surveillance but has also said he welcomed public debate on the balance between privacy and security.

The ACLU is asking the court to immediately halt the NSA’s vast tracking program of telephone calls, declare the program illegal, and order the government to purge all databases of the call records.

The case is American Civil Liberties Union et al v. Clapper et al, U.S. District Court, Southern District of New York, No. 1:13-cv-03994.