The National Security Agency used the Christmas holiday to "minimize the impact" of its release of compliance violations reports spanning 12 years and detailing unauthorized spying on American citizens, "vindicating" Edward Snowden, the American Civil Liberties Union said on Friday.

"I certainly think the NSA would prefer to have the documents released right ahead of the holidays in order to have less public attention on what they contain," Patrick Toomey, a staff attorney at the ACLU's national security project, told The Guardian.

The heavily redacted documents, released as the result of a legal challenge by the ACLU under the Freedom of Information Act, detail the repeated unauthorized surveillance of communications by American citizens, failure to follow legal guidelines pertaining to storing private information and sharing of data with unauthorized persons, reported The Intercept.

This summer, a court ordered the documents to be released by Dec. 22, and the NSA sent them to the ACLU by FedEx late on the 22nd. But Toomey told The Guardian that the ACLU didn't receive them until "late in the day on the 23rd." The agency posted the documents to its website at 1:30 p.m. on Christmas Eve.

Because of the number of redactions found within the documents, with many entries completely missing, it's difficult to determine how agents were disciplined for misusing data, or how quickly problems were solved, The Guardian noted, and Toomey suggested there could be a "large number of different compliance violations."

The sections detailing the total number of violations are also redacted, and the ACLU will continue to sue until those numbers are released, according to Toomey.

"There are certain portions of the documents that really vindicate some of the things [Edward] Snowden said when he first described the NSA surveillance in terms of the ability of analysts to conduct queries - without authorization - of raw internet traffic," Toomey said. "More generally, just the range of different compliance violations makes it clear that at every step of the NSA's collection of information there are vulnerabilities that leave the privacy of Americans at risk."

The NSA chalked the violations up to unintentional human error and technical mistakes and that in some cases, investigations led to disciplinary or administrative action.