Technologies like GPS and social media are posing new challenges to interpreting the Constitution's guarantees of privacy and free speech. Law professor and journalist Jeffrey Rosen says we're now in an era the Founding Fathers could never have imagined, in which private companies are determining the rules for what can be shared.

Technologies like GPS and social media are posing new challenges to interpreting the Constitution's guarantees of privacy and free speech. Law professor and journalist Jeffrey Rosen says we're now in an era the Founding Fathers could never have imagined, in which private companies are determining the rules for what can be shared.