500M calls. The number of unique phones is less. The real question is what fraction of these calls had both parties inside the US. That's a different categor

500M calls. The number of unique phones is less. The real question is what fraction of these calls had both parties inside the US. That's a different category than when one party is external/foreign — that's domestic espionage, which is a violation of law unless pre-authorized by the FISA court. THAT's the number I'd most like to know.