California passed a law boosting police transparency on cellphone surveillance. Here's why it's not working

Several years ago, little was known about the StingRay, a powerful surveillance device that imitates the function of a cell tower and captures the signals of nearby phones, allowing law enforcement officers to sweep through hundreds of messages, conversations and call logs. The secrecy around the technology, which can ensnare the personal data of criminals and bystanders alike, spurred lawsuits and demands for public records to uncover who was using it and the extent of its capabilities. In California, a 2015 law requires law enforcement agencies to seek permission at public meetings to buy the devices, and post rules for their use online. -- More...