Clapper knew darn well. Look up his comment about making the least untruthful answer.
This is EXACTLY why the NSA should not have this data. All it takes is a thug administration and we are all at risk.
He's the boss. In a highly compartmentalized organization like NSA even he doesn't get to know everything, or even half of everything ~ the compartmentalization is physical. If you've ever been to Mitre Corp, you figure out what's going on in seconds. They even have moveable walls ~ like a Sci Fi story, you may not go to the people you are supposed to meet with, but they can instantly put together a room around you to which they will go to meet you! Have had that happen there.
CIA in Langley is supposedly worse.
NSA has to use the same system.