After all, Clinton had been handling official business at the State Department like many Americans do with their personal business, on an unsecured server.

In sworn testimony before the Senate Intelligence Committee on March 12, 2013, Clapper said the NSA was not collecting, wittingly, "any type of data at all on millions or hundreds of millions of Americans," which presumably would have covered Clinton's unsecured emails.

But NSA contractor Edward Snowden's revelations – starting on June 5, 2013 – gave the lie to Clapper's testimony, which Clapper then retracted on June 21 – coincidentally, Snowden's 30th birthday – when Clapper sent a letter to the Senators to whom he had, well, lied. Clapper admitted his "response was clearly erroneous – for which I apologize." (On the chance you are wondering what became of Clapper, he is still DNI.)

I would guess that Clapper's confession may have come as a shock to then ex-Secretary Clinton, as she became aware that her own emails might be among the trillions of communications that NSA was vacuuming up.