On Wednesday, the supreme court will consider whether the government must obtain a warrant before accessing the rich trove of data that cellphone providers collect about cellphone users' movements. Among scholars and campaigners, there is broad agreement that the case could yield the most consequential privacy ruling in a generation.
Less appreciated is the significance of the case for rights protected by the first amendment. The parties' briefs make little mention of the first amendment, instead framing the dispute – for understandable reasons – as one about the right to privacy. Yet the court's resolution of the case is likely to have far-reaching implications for the freedoms of speech, press and association.
The case, Carpenter v United States, arises out of the government's prosecution of Timothy Carpenter for a series of armed robberies carried out in south-eastern Michigan and north-western Ohio several years ago. In the course of its investigation of the crimes, the government ordered Carpenter's cellphone provider to turn over data it had collected relating to Carpenter's movements. In response, the provider produced 186 pages listing every call that Carpenter had made over a 127-day period, as well as coordinates indicating where Carpenter had been at the beginning and end of each of those calls.