As we depend on our cell phones more and more, the tools to peek into our phones are getting better. Local police departments across the country are investing heavily in this technology. And, with few laws governing what police can collect and store, that has a lot of privacy advocates alarmed. NPR's Robert Siegel talks to City Lab reporter George Joseph about the spread of tools that let police collect cell phone data.
ROBERT SIEGEL, HOST: Increasingly, police departments are turning to military-grade surveillance tools to help fight crime - a trend that worries privacy advocates. A new investigation by CityLab, which is part of Atlantic Media, documents the spread of tools that let police collect cellphone data. CityLab reporter George Joseph joins me in the studio now. Welcome to the program.