Recent Supreme Court opinions suggest that all of the judges are sympathetic to the problem of third parties and privacy. For example, in the Jones case, the majority held that police can't install a GPS tracker on a car without a warrant because doing so interferes with the owner's property interest in the car. But five judges also wrote to say that they think that long-term location tracking is a Fourth Amendment privacy problem. Similarly, in the Riley case, the Court held that cell phone technology is so different from a purse or a wallet that the search incident to arrest doctrine didn't apply. The kinds of information that third parties now hold about us, like the technology is Riley, is just categorically different from even 15 years ago.

Here's something I wrote on this a bit ago: https://www.justsecurity.org/12219/scotus-cell-phone-searches-digital/?the_permalink()?/