The United States government demanded that Yahoo hand over massive amounts of data back in 2008 or be forced to pay a fine of $250,000 per day, according to the company.
The threat, which was disclosed in documents released by Yahoo on Thursday, is an example of how agencies such as the National Security Agency coerced tech companies including Yahoo, Google, Apple, Facebook and others to comply with PRISM, a data-collection initiative that gathered information about users of those firm's products.
Yahoo executives believed the program was unconstitutional, but lost a legal fight to prevent the government from accessing its records.
PRISM, which ended in 2011, and other government surveillance programs were first revealed to the world by media outlets such as The Guardian and The Washington Post. Both publications got their information from former NSA contractor Edward Snowden. PRISM gathered what's known as metadata about users, such as with whom they corresponded via email, though it did not gather the content of those messages.
Snowden's documents also revealed that the government accessed the data of Yahoo and other tech companies through a program called MUSCULAR, which allowed federal officials to tap into fiber optic cables that connected tech company data centers.
Many tech companies have been criticized for complying with the government programs, and this serves as Yahoo's attempt to show the public that it tried to fight broad data collection.
"We refused to comply with what we viewed as unconstitutional and overbroad surveillance and challenged the U.S. Government’s authority," said Yahoo General Counsel Ron Bell in a statement on the company's Tumblr. "Our challenge, and a later appeal in the case, did not succeed."
Yahoo lost its challenge in the Foreign Intelligence Surveillance Court, a shadowy court system that presides over government surveillance requests. Yahoo representatives have said the company has since fought to release the records pertaining to its case. The court has revealed 1,500 pages from the case in an attempt to demystify the legal basis for PRISM.
Those 1,500 pages still don't cover all of the case's documents, and Bell said Yahoo is working to declassify even more information. According to the Tumblr post, it is also working to make the newly available records accessible to everyone.