A Google data center in Council Bluffs, Iowa. Even online privacy advocates acknowledge that keeping personal data out of the hands of third parties is virtually impossible today. Connie Zhou/AP hide caption

itoggle caption Connie Zhou/AP

A promotional image from Renew shows one of its recycling/advertising kiosks in London. City officials asked the company to stop recording data about the phones of passing pedestrians. Renew hide caption

itoggle caption Renew

David Petraeus, then-CIA director, testifies before the Senate Intelligence Committee in January. Petraeus resigned Friday after acknowledging an extramarital affair. Karen Bleier/AFP/Getty Images hide caption

itoggle caption Karen Bleier/AFP/Getty Images