Yahoo sent a letter to U.S. Director of National Intelligence James Clapper with a request to clear up the matter of whether Yahoo received an order to scan its users' emails.

According to a Reuters report on Oct. 4, the company complied with an order from either the FBI or NSA to build a tool capable of scanning all its users' emails in search of a key phrase, purportedly in the feds' surveillance of terrorist chatter.

Forbidden to speak of the matter owing to FISA requirements, the letter to Clapper, now posted online, asks that the order be released from classified status so the company can offer the public details on its actions in the matter.

The disclosure, as well as a massive breach announced earlier, elicited a wave of negative publicity for the internet giant amid talks to be acquired by Verizon.