[jiggyboy]

The digital data at issue—personal location information maintained by a third party—does not fit neatly under existing precedents but lies at the intersection of two lines of cases. One set addresses a person’s expectation of privacy in his physical location and movements. See, e.g., United States v. Jones, 565 U. S. 400 (five Justices concluding that privacy concerns would be raised by GPS tracking). The other addresses a person’s expectation of privacy in information voluntarily turned over to third parties

I still can't figure out how my relationship with my bank or with my phone company has three "parties", and how my bank or my phone company is some distant "third party" and not the second party in that very tight relationship. That sleight of hand has enabled all of this warrantless searching.

Can somebody help me out here? Who's the "second party", if not the phone company?

[DesertRhino]

“Can somebody help me out here? Who’s the “second party”, if not the phone company? “

Nice catch. That is the Government that made themselves the second party almost without anyone noticing. Creeps.

[KrisKrinkle]

I still can't figure out how my relationship with my bank or with my phone company has three "parties", and how my bank or my phone company is some distant "third party" and not the second party in that very tight relationship. That sleight of hand has enabled all of this warrantless searching.

Can somebody help me out here? Who's the "second party", if not the phone company?

From the Original Post:

The other addresses a person’s expectation of privacy in information voluntarily turned over to third parties. See United States v. Miller, 425 U. S. 435 (no expectation of privacy in financial records held by a bank), and Smith, 442 U. S. 735 (no expectation of privacy in records of dialed telephone numbers conveyed to telephone company). Pp. 7–10.

Looks like in one case, the second party is whomever you did business with through the bank, for instance if you wrote a check or used a debit card to make a legal or illegal purchase and in the other case, the second party is whomever you called, whomever you "dialed up" using the phone company's service.

[Boogieman]

“Can somebody help me out here? Who’s the “second party”, if not the phone company”

The person on the other end of your telephone call?