The Anaheim Police Department of California admitted that they used special Cell Phone surveillance technology, known as DirtBox, mounted on aircraft to track millions of mobile users activities. The report also revealed that the police also purchased multiple Stingray devices, including one that can monitor LTE (Long Term Evolution) networks. DRTBox is capable of retrieving data from tens of thousands of mobile phones during a single flight in order to target criminals and suspects. The data on a vast number of innocent people are also being collected.
Source: https://thehackernews.com/2016/01/drtbox-cellphone-interception.html