If I'm a cell phone company and decide to just give the government access to all data I have pass through my systems, is that allowed? What if the government gives me some benefit in return for it?
> Lo and behold, Carpenter's general location information matched the robbery locations, and that information was used to help convict him. Carpenter appealed his conviction to the Supreme Court, contending that the Constitution required that police first obtain a warrant before getting this location information from a service provider.
This paragraph makes it seem like the govt must get a warrant before it can ask the service provider for that information.
FYI, the legal term you're looking for is "state actor". In case that helps with googling.