The logic is that they can sort through all of this data at their leisure and look for anything bad going on. The NSA and other governmental intelligence agencies have been doing this type of mass data collection for years, but now local law enforcement is getting in on the act. They are starting programs designed to track the movement of people through cell towers, license plate images and even facial recognition applications on traffic cameras.
Chicago and Anaheim are two cities that have been caught using this type of proactive police investigations. One area that has stood out is the use of Cellular intercept devices or DRT (Digital Receiver Technology) Boxes. These devices simulate a cellular tower and, by generating a stronger signal to the device, can force a device to switch to it for communication. In addition to this function they can decrypt the data and voice streams for recording or listening.
The American Civil Liberties Union was able to confirm that Anaheim was using these in large number across the city. The range of them actually included areas like Disneyland. The documents that they have published are heavily redacted, but would seem to indicate that the police department bought them covertly under their “covert purchase program”. The excuse they give is that modern phones have better encryption making it harder to listen into what they are doing. To add to the argument they also list that they will be put into place to recover abducted children.
It is the same old arguments; get the criminals and protect the children. The problem is that, on the surface, this type of device would automatically violate the 4th Amendment to the constitution which protects against unlawful search and seizure.
“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
If you turn this device on near a large group of people, they all are affected. Their voice and data streams a funneled into this device and decrypted. The vast majority of these people are not under any active investigation and their data and calls should remain private. Even in the event of an active investigation they should not be subjected this. There is no provision for local law enforcement to use this type of device in the interest of National Security and the FISA (Foreign Intelligence Surveillance Act of 1978) does not apply.
The good news is that California law now requires a proper warrant to use any device like this (Effective January 1 2016). That does not mean that you will not get caught up in an active investigation at some point, it just means that they cannot do it on a whim anymore.