[1]https://www.maryferrell.org/showDoc.html?docId=145022#relPageId=20&t
   ab=page
   "First it suggests that the NSA is able to monitor virtually every
   international communication entering or leaving the United States. At
   present, some 24 million telegrams and 50 million telex (teletype)
   messages enter, leave, and transit the United States annually,"

References

   1. https://www.maryferrell.org/showDoc.html?docId=145022#relPageId=20&tab=page