Our friends at the Electronic Frontier Foundation are suing the federal government, more specifically, the Department of Homeland Security, for information regarding their warrantless use of GPS devices.
Searches at a border have long been recognized to have far fewer Fourth Amendment protections based on the fact that something or someone is entering the country. However, as the law still needs to catch up with technological advances, revisions are being made to this principle and I predict there are more to come.
DHS was using the border search exception to the warrant requirement to justify placing GPS devices on vehicles that were coming into the country and track their movements throughout the country.
One salient question is: are they still doing it in light of Jones v. United States? This interesting article details some of the Foundation’s efforts to find out.