New York, October 5 (RHC)-- A report says the U.S. Internet giant Yahoo scanned hundreds of millions of users' emails in 2015 at the request of U.S. intelligence agencies.   According to the report published by Reuters on Tuesday, the company secretly built a custom software program last year to search all users’ incoming e-mails for specific information requested by U.S. intelligence officials.

Several former employees of the Internet company said the scanning of Yahoo Mail accounts was at the behest of the National Security Agency (NSA) or the Federal Bureau of Investigation (FBI).  "The request to search Yahoo Mail accounts came in the form of a classified edict sent to the company's legal team."

The company did not reject the report and without providing any further details, said: "Yahoo is a law abiding company, and complies with the laws of the United States."  Some experts said the move represents the first case in which a U.S. Internet company agrees to a spy agency’s demand to search all arriving messages.

"It is deeply disappointing that Yahoo declined to challenge this sweeping surveillance order, because customers are counting on technology companies to stand up to novel spying demands in court," Patrick Toomey, an attorney with the American Civil Liberties Union, said in a statement.

In a separate incident last month, Yahoo said "state-sponsored" hackers had gained access to 500 million customer accounts in 2014.  On several occasions, Internet companies have complained that the US government tried to force them to give away their users’ information.

Yahoo reported earlier this year that some 200 million accounts may have been accessed and that hacked data was being offered for sale on-line.  The users of Yahoo’s online services were urged to review accounts for suspicious activity.  They were also asked to change passwords.

The NSA has previously come under fire for spying on Americans’ phone calls and Internet communications.  

Countless leaks by American whistle-blower Edward Snowden have detailed the highly sophisticated tools used by the NSA to collect data in bulk from unsuspecting people, including American citizens.