One of the original cases establishing the third-party doctrine was US v. Miller (1976), where SCOTUS ruled that turning over deposit slips and checks to your bank removes your reasonable expectation of privacy. On the other hand, if you choose to opt out of using the banking system to avoid this, you'll need to use cash.
However, if you carry large amounts of cash, you're subject to warrantless seizure because of some sort of bizarre assumption that the only reason to opt out of the banking system is if you are a criminal.
This is an interesting point. If the only way to avoid submission of information to your bank is to forego banking services, then this is not a meaningful choice, and you're not giving up the information voluntarily.
"The submission of prescription information to the PDMP is required by law. The only way to avoid submission of prescription information to the PDMP is to forgo medical treatment or to leave the state. This is not a meaningful choice."
The law is rather clear, if dismal: privacy is not a right, only surprise violations of privacy are illegal. Once the government starts abusing people enough , it is no longer an expectation of privacy. See also the prohibition against "unusual" punishment.
However, if you carry large amounts of cash, you're subject to warrantless seizure because of some sort of bizarre assumption that the only reason to opt out of the banking system is if you are a criminal.