The courts place limits on the ability of police to monitor motorists through GPS devices, but officers can now obtain an even more detailed travel history report on every driver in an area using license plate cameras (ALPR, also known as ANPR in Europe). Under a federal court ruling last week, no warrant is needed to conduct a large scale surveillance operation with ALPR.

Such cameras were key to an April 2016 investigation of mail being pilfered from a post office in Las Vegas, Nevada. Postal inspectors used normal cameras to record a man in a GMC Yukon "fishing" through the affected mailboxes. That is, he dropped a string with adhesive material into the box so that he could pull the letters out. Jay Yang rented the Yukon seen in the video.

The investigators then turned to the massive license plate surveillance database maintained by Vigilant Solutions to obtain a travel history on the vehicles Yang had been using. A little over a third of Vigilant's database comes from government cameras and two-thirds from cameras mounted on private tow trucks. The database provided a report giving the Yukon's location, which allowed postal inspectors to set up a sting. A judge issued a warrant to search Yang's residence, which was found to have a stash of stolen mail, forged money orders and other illegal items.

US District Judge Richard F. Boulware II decided the warrantless use of the surveillance database did not violate the Fourth Amendment because motorists are supposed to have a lesser expectation of privacy. Judge Boulware acknowledged the US Supreme Court's ruling in US v. Jones restricted warrantless use of GPS trackers, but he noted that the main objection in Jones was that the GPS device -- unlike ALPR cameras -- follows motorists onto private property.

"The court finds that the license plate image of the GMC Yukon and the location of the observation in the [Vigilant Solutions] LEARN detection report was obtained from a digital camera while the GMC Yukon was on a public street and before it entered into any private property or private gated community," Judge Boulware ruled. "Yang does not have a reasonable expectation of privacy in the observation (and location of the observation) of the license plate of the vehicle he is driving on public streets with other vehicles."

The court went on to argue that there was no privacy intrusion under the Fourth Amendment because government agents did not search anything that belonged to Yang.

"The court does not find that there was any form of 'electronic trespass' that might implicate a reasonable expectation of privacy," Judge Boulware ruled. "The location information in this case was not generated by Yang electronically or digitally surrendering private or confidential information to a third-party working in cooperation with law enforcement."

A copy of the ruling is available in a 100k PDF file at the source link below.