It was reported recently that Yahoo complied with a secret order to scan all incoming emails of its users for the NSA and the FBI. The report claimed that Yahoo developed a special software program to make this happen. More details have emerged about how this came to be. The latest report claims that Yahoo tweaked a filter intended to screen emails for child pornography and spam to scan incoming emails for a computer “signature” linked to the communications of a state-sponsored terrorist organization.
The New York Times reports that Yahoo customized the existing scanning system for all incoming emails which stored and made available to the FBI a copy of any email messages that it detected as containing that digital signature. The sources cited in the report claim that the process of scanning all incoming emails is no longer taking place.
The report adds that the Justice Department got an individualized order from a judge of the Foreign Intelligence Surveillance Court last year to get Yahoo to do this, the company was naturally barred from disclosing what it had been ordered to do.
Investigators were following leads after learning that agents of a foreign terrorist organization were communicating using Yahoo’s email service and that their method used a “highly unique” identifier or signature, but investigators were unaware which specific email accounts those agents were using.
Yahoo hasn’t gone into details as yet, it called the first report which broke this story “misleading” and later issued a statement which claimed that “The mail scanning described in the article does not exist on our systems.”