Regular readers know that I am concerned that the accumulation of many small legal actions can create a violation of privacy that exceeds the sum of the observations. This week, the DC Circuit Court ruled that prolonged recurring legal acts can become an illegal search, or one that requires a specific warrant. If it stands on appeal, this theory may be one of the most important decisions to protect individuals and restrain the modern state ever.
The ruling defines a new "mosaic" theory of the Fourth Amendment under which individual law enforcement actions that are not searches to become a search when collected together. This is an important new theory. Noted fourth amendment scholar Orin Kerr has written how this throws decades of decisions on their head. Lawyers, though, worry about clear predictability of the law more than about theory and justice and the proper balance between the individual and society.
In the case United States v. Maynard, the court ruled that the long term use of a GPS device to monitor a car required a warrant. The government argued that roads are public, and that it could have had a watched public acts on public roads if it wanted; automating that information gathering was no big deal. According to the court, "[T]hat whole reveals far more than the individual movements it comprises. The difference is not one of degree but of kind, for no single journey reveals the habits and patterns that mark the distinction between a day in the life and a way of life." Exactly.
One purpose of constitutional law is to provide a basis for understanding bodies of law as well as individual laws. Law is made up primarily by decisions accumulated over time, in response to uncomfortable circumstances. A small bad decision supports another slightly worse decision until the law is firmly behind something few would choose. Plessey vs. Ferguson, the famous case that defined separate but equal as the law of the land was uncontroversial when passed, unexamined for 50 years, and supported by precedent and cemented by rulings that followed. It was good that we overturned that body of law.
In a similar way, we have been building a series of decisions about the use of technology and surveillance that must be overturned. The law has been willfully ignorant about technology and change. Perhaps it is because judges are older when appointed, and isolated from wider business. Perhaps it is because judges are discouraged from speculating on their thoughts and motives in public. Perhaps they are simply overly deferential to congress and police.
Judges have ruled that the information on personal computers are neither personal “papers or effects”. The current administration is arguing that searches of cell phones, including modern smart phones with call logging, email, documents, and passwords for accessing personal and business web sites, do not require a warrant. For whatever reason, judges have not given sufficient respect to digital papers and digital effects.
I have written before that accumulating data creates something that is of a different quality than each datum, and that quality is more dangerous as the points accumulate. I have written that there is danger to the citizenry even in gathering data required to operate a business, when it is shared outside the purposes of that business. I now know to call this the mosaic theory.
The government will certainly appeal United States v. Maynard. It may be overturned. If it is not, it creates a legal theory that may be held not only against police actions of the government, but against the misuse and re-sale of information gathered in e-commerce. It establishes a legal theory for discussing the repurposing of operational data.
It might help change to direction of the smart grid. Direct load control of homes and commercial buildings collects millions of data points that create their own mosaic. These mosaics will combine with mosaics from the internet and e-commerce. If every market is the sum of the participants knowledge problems, then not only privacy, bit all markets are changed, as one set of participants accumulates an immense imbalance of knowledge about the other.
Economic signals in smart energy collect less personally identifiable details than do direct load control models. We should all prefer them, rather than contribute more to the mosaic owned by others, and created to achieve advantage over each of us as individuals.