After a recent ruling by the Eighth Circuit, police can access the information on the back of your credit/debit/gift card without having to obtain a search warrant first. Why? Because it's not a search under the Fourth Amendment, the circuit ruled. If this doesn't scare you, perhaps it should, because it has the potential to undermine the digital privacy law as recently laid out by Riley v. California.
Here, there seems to be a colorable argument to be made that the Eighth Circuit's opinion cuts against a reasonable application of Riley as it might apply to credit cards. Should cell phone law apply to magnetic strips?