In its 1966 decision Miranda v. Arizona , the United States Supreme Court guaranteed  every American the right to remain silent, the right to an attorney, and If you cannot afford an attorney, the right to have one appointed for you. Unfortunately for citizens detained by the police today, the Supreme Court did not, however, guarantee anyone the right to not have the police confiscate their cell phones, turn them on, and start merrily scrolling through their Facebook postings.

You can't really blame them for that. In 1966, cell phones hadn't yet been invented. But now that they have been invented, and now that many Americans are carrying around the digital lives in glowing, Gorilla-glassed, 3" x 5" silicon, aluminum, and carbon fiber boxes, the question of whether the police can seize and access your cell phone without a warrant has finally come to the fore.

Apple's iPhone5S -- Is it a 21st Century digital wallet? And is it just as subject to warrantless search? Photo: Apple.

This week, the U.S. Supreme Court addressed this issue in a pair of cases orally argued before it. In Riley v. California a driver detained at a traffic stop had his cell phone searched, revealing photos and videos linking him to a gang-related shooting. And in United States v. Wurie police arresting a Boston-based drug dealer used his cell phone contacts list to locate a stash of cocaine.

Appellate lawyers arguing the government's position in both cases say that cell phones today are the electronic equivalents of 20th century wallets and address books. They're items that if discovered in a "search incident to arrest," may be legally flipped through by the police in a quest for evidence of a crime.

Advocates for the privacy rights counter that while it's true cell phones today perform many of the same functions as wallets stuffed with money, scraps of paper notes, business cards, and family photos, they also contain a whole host of other data that most people expect to be able to keep private from prying eyes -- credit card numbers, medical records, emails, and the like. They argue that if the police want access to such information, they should first prove they're legally entitled to it -- by asking a judge to issue a search warrant.

So what?
Were the suspects in the Riley and Wurie cases guilty of the crimes they were, ultimately, convicted of? Probably, yes.

Would the police have to let the criminals walk if the Supreme Court decides they had a constitutional right to privacy in their cell phones? Possibly, also yes. (But possibly also no, if prosecutors can prove they would have found the evidence needed to convict by other means anyway, eventually).

In any case, there's an old adage in legal circles: "Hard cases make bad law ." The decision the Supreme Court must make as it considers the cases of Riley and Wurie over the next couple months is whether it's worth letting a couple of smalltime criminals off the hook to preserve everyone else's right of privacy in their digital wallets -- or whether those wallets deserve any privacy protections in the first place.

That's a decision that will affect all of us.

Will your cell provider stand for it?
The implications of a loss of privacy rights to the data contained on a cell phone, from a personal perspective, should be obvious. Less obvious to investors might be the implications that a Supreme Court ruling -- permitting warrantless "searches" of cell phones -- could have for the companies we choose to do business with and even invest in.

For one thing, such a ruling would quite likely spark heightened interest among cell phone users in making it more difficult for police to gain access to data contained in their phones -- with a warrant or not. It could, for example, make the new fingerprint identification sensor on Apple's (NASDAQ:AAPL) new iPhone 5S a "must-have" feature in competition with cell phones that lack such authentication technology. More broadly, though, cell phone users understand that anything that can be encrypted or password protected can be decrypted and hacked by the police.

So what effect might a ruling that weakens privacy protections on cell phones be expected to have on cell phone owners? It might make them more cautious about using their cell phones for the kinds of data intensive applications  that wireless operators such as Verizon (NYSE: VZ) and AT&T (NYSE: T) depend on to drive revenue growth. You'd probably think twice about downloading prurient pictures, YouTubing videos of questionable conduct, or downloading an mp3 file of Coolio's Gangsta's Paradise. It might even short-circuit the movement of many users away from desktop computing (largely protected  from warrantless search) toward "mobile computing" -- now riskier in an age of search incident to arrest.

In short, an adverse Supreme Court ruling in Riley and Wurie could be bad news for cell phone users... and for many of the companies that cater to them as well.


Rich Smith owns shares of Apple. The Motley Fool recommends Apple and Facebook. The Motley Fool owns shares of Apple and Facebook. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.