Yahoo Inc. allegedly secretly developed and implemented custom software it used to scan Yahoo email accounts for incoming messages in search of specific information given to Yahoo by U.S. intelligence. In an exclusive report released Tuesday, Reuters reports that Yahoo was acting in compliance with a classified directive from the government when it scanned all customer emails.

This amounts to hundreds of millions of Yahoo email accounts being tracked for information that has not been made public, though Reuters reports that it was unable confirm if Yahoo turned over any information to the government. According to Reuters, the information was requested by the National Security Agency (NSA) or the FBI, citing anonymous former Yahoo employees and a third person who was aware of the software and the directive.  

The software was reportedly discovered by Yahoo's own security team in May of last year, according to Reuters. Initially, Yahoo security employees thought that hackers had illicitly installed the program. 

This is hardly the first time a communications company has agreed to provide government offices with the private information of customers. However according to former government officials and private surveillance experts who spoke with Reuters, this is perhaps the first time the government has requested such broad spying on customers, as well as the first time new software was required to get the job done. 

While Reuters was unable to confirm, it's report states that it is likely other internet companies were asked for equally broad access to customer emails.

NSA whistleblower and former CIA employee Edward Snowden tweeted about the new report Monday, telling anyone with a Yahoo email address to close down their account.

In a statement to Reuters regarding the allegations, the company said, "Yahoo is a law abiding company, and complies with the laws of the United States." Yahoo reportedly refused to comment further.