Thompson v. Wilson Brief: Installing a Permanent GPS Monitor on a Boat Is a Fourth Amendment Seizure

Matthew Cavedon

In March 2022, the Atlantic States Marine Fisheries Commission directed member states to require that all federally permitted lobstermen affix GPS tracking devices to their vessels. Maine complied by promulgating a rule (the MDMR Rule) compelling Petitioner Frank Thompson, along with other Maine lobstermen—to attach a device to his boat that transmits his location to the government once every minute, every hour, every day—including when the vessel is docked and when Thompson is using it for personal purposes. The device has no off switch for the end of the workday. It does not pause when Thompson needs to shuttle a family member to the mainland. It runs continuously, generating a detailed, permanent record of Thompson’s movements that the government may retain and mine indefinitely.

Thompson filed suit in federal court to challenge the MDMR rule as a violation of his Fourth Amendment right to be free from unreasonable searches and seizures. On appeal, the First Circuit upheld the Rule as a permissible search based on its application of the administrative search exception outlined in New York v. Burger, 482 U.S. 691 (1987).

The First Circuit’s analysis misses a threshold question. The Fourth Amendment prohibits unreasonable searches and unreasonable seizures. Each government action requires separate analysis. By compelling Thompson to permanently affix a government GPS device to his boat, Maine has meaningfully interfered with his possessory interest in his property. That is a seizure. The administrative search exception addresses searches. Its application in this case cannot authorize a seizure of Thompson’s property.

Even under the administrative search exception, the First Circuit’s decision cannot stand. A warrant exception cannot authorize a search that no warrant could. Burger’s three-prong test was designed to ensure that administrative searches stay cabined to the same limits a warrant requires, not authorize far broader searches. The First Circuit’s analysis imposes no meaningful restraints on a search’s necessity, method, or scope. It turns an exception into a windfall.

The First Circuit’s error will not stay confined to Maine’s lobstermen. The decision creates a replicable framework under which any agency may impose continuous GPS tracking with no judicial oversight and no endpoint. The Supreme Court has already recognized that technology-enabled location tracking poses a serious threat to the Fourth Amendment. That threat is amplified by the vast number of industries that have already been accorded “closely regulated” status. The First Circuit’s decision would subject every one of those industries to mass surveillance. The Fourth Amendment’s protections cannot weaken as regulation expands.

Cato, joined by the National Federation of Independent Business Small Business Legal Center, filed an amicus brief asking the Supreme Court to grant Thompson’s petition and reverse the judgment.