The NSA would like you to know that, while it may have data on millions of phone calls from US carriers, it only sought detailed information on less than 300 phone numbers. That's according to an (unclassified) government memo making the rounds, reports Reuters, in an apparent attempt to underscore that the spying was limited in scope. But the spying apparently paid big dividends, breaking up "dozens of potential terrorist plots here in the homeland and in more than 20 countries around the world." Notable among them was a 2009 plot to bomb the New York City subway, adds Fox News. American intelligence officials say they're working to declassify more cases to prove the merit of the system.