Buying Data and the Fourth Amendment

Can governments purchase user records as an end-run around the warrant requirement imposed by Carpenter v. United States? As a matter of Fourth Amendment law, the answer is “yes.” Companies have common authority over their business records. Common authority allows companies to consent to a government search of their databases even when their users oppose it. A voluntary sale manifests consent, permitting the government to buy access to Carpenter-protected records without a warrant or cause. Arguments exist for why a different rule may be justified someday. But for now, and for the foreseeable future, Fourth Amendment law permits buying business records even if users have rights in those records.

You can read the paper here and below: