The US Justice Department issued guidelines for StingRay Surveillance devices, new rules define aim to ensure privacy protection and transparency.
Do you know what is a StingRay? If you want further details give a look to a post I wrote for the Infosec Institute on the StingRay Technology:
"StingRay is an IMSI-catcher (International Mobile Subscriber Identity) designed and commercialized by the Harris Corporation. The cellular-surveillance system costs as much as $400,000 in the basic configuration, and its price varies with add-ons ordered by the agency.