After several freedom-of-information requests, the New York Civil Liberties Union (NYCLU) announced yesterday:
"In response to an NYCLU FOIL request, the NYPD disclosed it used Stingrays nearly 1,016 times between 2008 and May of 2015 without a written policy and following a practice of obtaining only lower-level court orders rather than warrants. This is the first time the extent of the use of Stingrays by the NYPD has been made public... Authorities are able to conduct this surveillance without the involvement of cell phone companies... The NYPD also disclosed that it has no written policy for the use of Stingrays but that, except in emergencies..."
Stingrays are devices that simulate real cellular phone towers in order to track and collect data about phone users. Your phone cannot distinguish between a real and simulated cellular tower. The data collection affects many people besides the persons being tracked:
"... in some configurations, [stingrays] collect the phone numbers that a person has been texting and calling and intercept the contents of communications. Stingrays also sweep up information from nearby bystander cell phones even when used to target specific phones..."
So, you can be completely innocent, and still be tracked. Not good. The U.S. Justice department implemented a new policy in September 2015 requiring probable-cause warrants for some usage. Stingrays are used by federal, state, and local law enforcement in at least 18 states. Stingrays are used far beyond New York City:
"Last April, the NYCLU released records showing the Erie County Sheriff’s Office had used Stingrays 47 times in the last four years and only once indicated obtaining a pen register order before doing so... In May, NYCLU FOIL requests also revealed that the New York State Police spent hundreds of thousands of taxpayer dollars on Stingrays and related equipment."