Director of National Intelligence James Clapper, seen here in 2013. (credit: Partnership for Public Service)

Yahoo’s top lawyer published an open letter on Wednesday, “demanding” that the Office of the Director of National Intelligence “provide clarity” about whether the company was ordered to perform mass spying on all of its users.

Earlier this month, Reuters reported that Yahoo “complied with a classified US government directive, scanning hundreds of millions of Yahoo Mail accounts at the behest of the National Security Agency or FBI, said two former employees and a third person apprised of the events.” It is not clear what data, if any, was handed over.

If such an order exists, Yahoo would almost certainly be forbidden from discussing it publicly lest it face legal sanctions.