The National Security Agency again improperly collected records of American phone calls and texts last year, according to documents made public Wednesday.
It was the second time the U.S. security agency has gathered unauthorized and inaccurate data in a program that violates federal law.
The error occurred between Oct. 3 and Oct. 12, 2018, according to documents obtained and released by the American Civil Liberties Union (ACLU).
It comes months after the NSA said it had destroyed millions of records it had collected since 2015 due to a separate error.
"These documents further confirm that this surveillance program is beyond redemption and a privacy and civil liberties disaster,'' Patrick Toomey, staff attorney with the ACLU's National Security Project, said in a statement. "The NSA's collection of Americans' call records is too sweeping, the compliance problems too many, and evidence of the program's value all but nonexistent. There is no justification for leaving this surveillance power in the NSA's hands.''
The ACLU says the information about the latest violation shows it had a "significant impact" on privacy and civil rights, but that the Americans affected were not told of the breach.
NSA's phone data collection program began in secret after the attacks of Sept. 11, 2001. Several major phone companies began providing the NSA with daily records of their domestic landline calls.
The existence of the program came to light when renegade NSA contractor Edward Snowden leaked information on U.S. surveillance techniques. It was greatly scaled down by the passage of the USA Freedom Act, which requires the government to make a request to the relevant telephone company for data based on a specific person, account, address or device.