A lot of the arguments for allowing such searches (including Justice Alito's) assert that the information in a cell phone is not substantially different from what police might find in a wallet, which they are allowed to search without a warrant. Sane people, on the other hand, argue against such searches, recognizing that a modern cell phone can hold much of the data about a person's entire life, unabridged, and that searching it is like searching "houses, papers, and effects" ... your computer, your file cabinets, your personal phone directory, your photo albums, etc., and therefore violates the Fourth Amendment.
A good place to begin... always... is with SCOTUSblog's "In Plain English" series entry for the case, which is here. As few of my readers are lawyers, I'm going to leave you with that for tonight, and await more analysis as it comes out. There's no way I'm going to attempt to guess what the Court, which has no clear majority for either the government's case or the defendant's, will decide in a compromise. I don't envy them their work. Even Scalia... EVEN SCALIA! ... has serious doubts about the government's case.
What I can tell you is this: in one article I ran across today, it was asserted that 90% of Americans (cell phone owners, I believe they meant) have smartphones. I am among the 10% with a junky old dumb phone. I have lately contemplated buying a smartphone, which means one for me and one for Stella. Like most Americans, she is fascinated with the possibilities. I, on the other hand, am horrified at the kinds of police fishing expeditions a smartphone combined with any kind of aggressive ruling in this case could enable. No, thank you; if warrantless searches on a law enforcement officer's mere whim are authorized in law, you can forget about my carrying anything easy to search. And if any of you know how to password-protect older cell phones, I'd appreciate knowing how to password my old Samsung.
Other worthwhile references:
- Constitutional Accountability Center, here, here and (if they ever get it working) here.
- epic.org on Riley. Contains EPIC's amicus brief.
- Business Insider's very, very short summary.
- Orin Kerr on Volokh's WaPo blog.