Social media

New York Times advice columnist Philip Galanes details how to handle breakups, cellphone calls and food allergies — among other topics — in his book Social Q's: How to Survive the Quirks, Quandaries and Quagmires of Today.

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.

Facebook, Google, Amazon and Apple are expanding rapidly into finance, advertising, media and retail. Tech writer Farad Manjoo outlines how the four companies are heading in new directions -- and encroaching on each other's territory -- as they try to expand their customer base.