If you live in Naperville, Ill. and want electricity, you have no choice but to buy it from the city, which has smart meters that collect energy consumption data every 15 minutes and store them for up to three years. Concerned residents: The data reveal when people are home or away, their sleeping routines, and more. Seventh Circuit: No Fourth Amendment problem here. The gov’t has a significant interest in providing effective utility services, and the risk of the data being used for law enforcement purposes is minimal.