<quote>The NSA has admitted, separately, that it employs a practice called "contact chaining." That means that if one of their targets calls someone, who in tur

<quote>The NSA has admitted, separately, that it employs a practice called "contact chaining." That means that if one of their targets calls someone, who in turn calls someone else, who in turn calls you, agency's checking you out.</quote> Ah. So when you get an appointment reminder from your dentist, you might just have been chained with a suspect who called that same dentist earlier. Or maybe your girl/boy-friend works at Domino's on the side and called you from there, and it so happens a suspect is one of their customers.... congrats, NSA file for you.