For several years, the National Security Agency unlawfully gathered tens of thousands of emails and other electronic communications between Americans as part of a now-revised collection method, according to a 2011 secret court opinion.

The redacted 85-page opinion, which was declassified by U.S. intelligence officials on Wednesday, states that, based on NSA estimates, the spy agency may have been collecting as many as 56,000 ¡°wholly domestic¡± communications each year.

In a strongly worded opinion, the chief judge of the Foreign Intelligence Surveillance Court expressed consternation at what he saw as a pattern of misleading statements by the government and hinted that the NSA possibly violated a criminal law against spying on Americans.