The NSA has gone out of legal bounds perhaps as much as thousands of times in any given year, according to internal audit documents obtained by The Washington Post from leaker Edward Snowden.

The 2012 audit documents not only reveal outright violations of the law, but in some cases also show deliberate efforts to obfuscate what the intelligence agency was actually doing, The Post reports.

In one instance, the NSA decided that it need not report the unintended surveillance of Americans. A notable example in 2008 was the interception of a ‘large number’ of calls placed from Washington when a programming error confused the U.S. area code 202 for 20, the international dialing code for Egypt, according to a ‘quality assurance’ review that was not distributed to the NSA’s oversight staff.

Meanwhile, The Post has also published comments from U.S. District Judge Reggie B. Walton, chief judge of the Foreign Intelligence Surveillance Court (FISC), which show that for all it’s efforts to monitor intelligence projects, the court is limited in monitoring what the NSA and other intelligence services are actually doing.

‘The FISC is forced to rely upon the accuracy of the information that is provided to the Court,’ its chief, U.S. District Judge Reggie B. Walton, said in a written statement to The Washington Post. ‘The FISC does not have the capacity to investigate issues of noncompliance, and in that respect the FISC is in the same position as any other court when it comes to enforcing [government] compliance with its orders.’