Being able to read everyone's email is a matter of national security... by reading emails the government can anticipate and foil a terrorist attack better than if say a woman on the terrorist watch list has a son that goes to Russia and comes back and the Russians tell us that Tamerlan Tsarnaev has been radicalized and is a danger to our country and we do nothing about it and he blows up an 8 year old, kills two more and maims hundreds. If we don't take seriously an explicit warning who thinks scanning billions of emails will be effective?

USA coast to coast great circle distance is about 3,400 kilometers which is 3,400,000 meters or 340,000,000 cm... divided by 78,000 persons is about 4,400 cm per person... or 44 meters... seems someone is off by a factor of 100.