That's a key question for this case, yeah. United States v. Graham held, with significant controversy, that obtaining historical location data from a phone com

That's a key question for this case, yeah. United States v. Graham held, with significant controversy, that obtaining historical location data from a phone company is shared with a third party and so lacks 4th Amendment protection. But the Massachusetts court finding for this case centered on the ping; law enforcement can't ask third parties to conduct specific searches in its place, which was effectively what they did here. (Similarly, there's a standing case about the FBI use of paid GeekSquad informants which hinges on whether they were being paid for discoveries in the course of work, or implicitly hired to conduct searches.) That said, two judges here held that even if the Fourth Amendment doesn't protect location data, the Massachusetts constitution does. So once the targeted-request program ends, we may see this question revisited.