GPS Decisions Are Consistent With A Traditional Fourth Amendment Approach -- But Some Disagree.

An American University Law Student has published an interesting note on the Maynard decision. 

The Note by Bethany Dickman is titled, Note: Untying Knotts: The Application Of Mosaic Theory To GPS Surveillance in United States v. Maynard,  60 Am. U.L. Rev. 731 (2011).

I want to highlight one aspect of the Note.  Ms. Dickman argues that the Maynard decision is an example of the “mosaic theory” of the Fourth Amendment.  Under this theory – perhaps over-simplifying a bit – a number of otherwise permissible techniques can, in the aggregate, constitute an impermissible search for Fourth Amendment purposes.  Dickman explains:  “privacy may exist in the aggregate of one's movements, despite their inherently public character.” 

This theory is likely a nice description of the state of affairs.  However, I remain unconvinced that the Maynard decision, and other decisions holding that the use of GPS tracking devices, represent a leap towards a new theory or approach to the Fourth Amendment.  From a practical standpoint that is undesirable, as it would upset the expectations of law enforcement, judges, prosecutors, and defense attorneys.

In my view, the decisions invalidating the use of GPS devices, like Maynard , are limited to the precise situation.  The mosaic approach to the Fourth Amendment would be inappropriate in other contexts, such as a review of cell phone call records.  Instead, these decisions are best understood, I believe, as part of the traditional recognition by courts that technological advances in surveillance techniques have made possible intrusive government interference with privacy without a physical invasion.   The protections provided by the Fourth Amendment, as the Supreme Court has often recognized, change to meet new technology.  

It is important to remember that the use of GPS tracking devices for long-term surveillance is not merely an enhancement of the type of surveillance traditionally conducted by police, as no police agency could deploy the skill and resources to, undetected, record the type or amount of information provided by a GPS tracking device.  Under traditional Fourth Amendment approaches, a warrant is required because no reasonable person would expect to be the target of such a massive police surveillance operation.