“Thankfully,” he said, “the US Supreme Court has sent a resounding message to government officials – especially law enforcement officials – that there are limits to their powers.”
Although all nine justices agreed that the government’s use of a GPS tracking device amounted to a search, the justices split 5 to 4 on how to properly analyze the issue.
Writing for the court, Justice Antonin Scalia tied the question to Fourth Amendment protections of the sanctity of private property against government trespass. He said the government needed a warrant not just to attach the GPS device to a piece of private property, but to attach the device with the intent of obtaining information.
“We have no doubt that such a physical intrusion would have been considered a ‘search’ within the meaning of the Fourth Amendment when it was adopted,” Justice Scalia wrote in an opinion joined in full by four other justices.
Justice Samuel Alito agreed with the general outcome of the case, but wrote separately to suggest the court should have based its decision on an examination of whether the owner of the monitored vehicle had a reasonable expectation of privacy in the long-term movements of his car.