Police in several major cities have been trying out a new form of surveillance that calls into question our perceived sense of privacy. One of the pioneers in this field, Persistent Surveillance Systems (PSS), has created a method for providing constant, real-time aerial surveillance of entire swaths of major metropolitan areas. Using high-powered cameras mounted under aircraft and sophisticated processing techniques, PSS is able to auto-stabilize and stitch together angles from different cameras into a seamless map of the city. In the words of PSS founder, Ross McNutt, “Imagine Google Earth with TiVo capability.”
But is this legal? A couple United States Supreme Court cases come to mind when considering this. Florida v. Riley involved aerial surveillance by a police helicopter. The defendant was growing marijuana in a greenhouse in his backyard. Two of the greenhouse roof panels were missing, giving an unobstructed view into the grow operation from the air. The police spotted the marijuana from an altitude of 400 feet in a helicopter. Based on those observations, the police obtained a search warrant for the greenhouse.
The Court upheld the actions of the police, saying there was no reasonable expectation of privacy in the home from the air at altitudes navigable by the public. Since a private citizen could’ve flown over the greenhouse at 400 feet and spotted the marijuana, so could the police.
However, PSS’s real-time surveillance capabilities bring up additional concerns beyond mere observation; that of tracking. In United States v. Jones, the defendant was suspected of trafficking narcotics. Police installed a GPS tracking device under the defendant’s vehicle and tracked him for twenty-eight days. Based in part on the information from the GPS tracking device, the defendant was charged in a multi-count indictment.
The Court examined whether the installation of the GPS device constituted a trespass by the government, requiring a warrant. The Court found that it did, stating that a “search” occurs, at a minimum, whenever the government obtains information by physically intruding (trespassing) on a constitutionally protected area. However, the Court went on to note that electronically tracking movements of individuals might be illegal, even without the physical trespass.
It is clear that police are allowed to observe activity that any private citizen could observe without a warrant. It is also clear that physically installing a tracking device on someone’s vehicle does require a warrant. But whether PSS’s warrantless electronic aerial surveillance is legal is still an open question.