“It’s a very serious and egregious security violation,” Clapper said on CNN’s “Erin Burnett OutFront” of bringing a phone into the White House Situation Room.

“It’s sort of an honor system where everybody knows not to do that.”…

Clapper added, “You’re expected as a responsible member of the President’s security team not to do that. … So it’s just kind of unthinkable that that would happen.”