I'd agree that the 4th Amendment ought to cover it.
It isn't unambiguous, though. It isn't hard to see how a lawyer could point out that "and to forever secure the people, their persons, houses, papers, and effects, against all unreasonable searches and seizures under the guise of law" says nothing about purchasing data from a 3rd party. This wasn't really something that would have come up in the 18th century.
Extending the letter to match the spirit is why reflection is built into the runtime of the current constitution.
And furthermore can they reverse the order of said invasive search and payment through a wink-wink arrangement? I think the case is pretty strong against the government here. The EFF should bring a suit.
The intentions that 3rd party has changed, but having a PI follow a suspect, or coercing (with money or threats) a CI to provide information predates computers and the Internet and probably the Industrial Revolution as a police tactic by a huge margin.
Purchasing "data" from a 3rd party is a modern Internet spin, but it's not like the concept is brand new to the law or the legal department.
It isn't unambiguous, though. It isn't hard to see how a lawyer could point out that "and to forever secure the people, their persons, houses, papers, and effects, against all unreasonable searches and seizures under the guise of law" says nothing about purchasing data from a 3rd party. This wasn't really something that would have come up in the 18th century.
Extending the letter to match the spirit is why reflection is built into the runtime of the current constitution.