Internet companies including Google, Facebook, Microsoft and Yahoo were paid millions of dollars by the NSA to cover the cost of participating in the Project Prism data collection programme.
Declassified documents showed the Foreign Intelligence Surveillance court (FISA) ruled the NSA was violating the 4th Amendment (prohibiting unreasonable seizures and searches) in a October 2011 ruling.
The court deemed the NSA was breaching the 4th amendment because it was unable to separate domestic communications from foreign traffic.
Up until this ruling, the NSA had relied on the FISA court to provide annual certifications for data collection. After the ruling these were limited to temporary renewals.
Further documents released by the Guardian appear to show this coincided with a financial relationship between the NSA and the high-profile firms.
"Last year's problems resulted in multiple extensions to the certifications' expiration dates which cost millions of dollars for PRISM providers to implement each successive extension costs covered by Special Source Operations," noted a top-secret memo from the NSA dated December 2012.
In a statement, Yahoo acknowledged that it had been reimbursed for the compliance procedures that it had been obliged to follow.
"Federal law requires the US government to reimburse providers for costs incurred to respond to compulsory legal process imposed by the government. We have requested reimbursement consistent with this law," the web giant noted.
Similarly, Microsoft claimed it only ever complies with court orders because it is legally required to and not because it is paid for the work.
"We [Microsoft] could have a more informed discussion of these issues if providers could share additional information, including aggregate statistics on the number of any national security orders they may receive," the firm said in a statement.
Meanwhile, Google noted that it is still waiting for the US government to publish more information about data requests.
"We await the US government's response to our petition to publish more national security request data, which will show that our compliance with American national security laws falls far short of the wild claims still being made in the press today," Google said.
