Yahoo has won a court ruling that allows the release of records that show how the web firm fought against demands to hand over data under Prism, when the web monitoring system was first established in 2008.
A court ruled that the United States Department of Justice (DoJ) must reveal previously classified documents, which, according to Yahoo, will show that the firm didn't want to provide the US government with information about its users.
"The government shall conduct a declassification review of this Court's Memorandum Opinion of [the case] and the legal briefs submitted by the parties to this Court," the ruling said, adding "After such review, the court anticipates publishing that Memorandum Opinion in a form that redacts any properly classified information."
The DoJ has two weeks to inform the court how long it believes it'll take to redact the necessary parts of the report before it can be made viewable to the public.
The ruling in favour of Yahoo was made by the Foreign Intelligence Surveillance Act (FISA) court – the same body that signed the order that required Yahoo to provide the government with information about its users in the first place.
Civil liberty group the Electronic Frontier Foundation (EFF) praised Yahoo for its fight against Prism, awarding it a star of special distinction in its "Who Has Your Back" survey.
"Yahoo went to bat for its users - not because it had to, and not because of a possible PR benefit - but because it was the right move for its users and the company. It's precisely this type of fight - a secret fight for user privacy - that should serve as the gold standard for companies, and such a fight must be commended," said EFF in a statement.
"While Yahoo still has a way to go in the other Who Has Your Back categories (and they remain the last major email carrier not using HTTPS encryption by default), Yahoo leads the pack in fighting for its users under seal and in secret."
The EFF also suggests that other organisations may also have taken the fight to Prism.
"We encourage every company that has opposed a FISA order or directive to move to unseal their oppositions so the public will have a better understanding of how they've fought for their users," it said.
HP privacy officer Daniel Pradelles recently told Computing that the firm would put up a fight to protect its customers' data if the US authorities requested that it be handed over.
Yahoo recently revealed that from December 1 2012 to May 31 this year, it was subject to over 12,000 data requests by US government agencies under Prism, as authorities looked to gain information about citizens without their consent.