Police uncovered Brima Wurie's drug dealing during a routine arrest in Boston six years ago, thanks in part to the frequent calls from "my house" arriving on his flip-top cellphone.
David Riley's participation in a San Diego gang shooting in 2009 was revealed after police stopped his Lexus for having expired tags, found weapons and eventually located incriminating photos and video on his smartphone.
Cellphones - owned by more than nine in 10 American adults - are at the center of a growing legal debate over privacy rights and technology, one that's probably headed to the Supreme Court in the coming months.
As the Wurie and Riley cases illustrate, your cellphone and the intimate information it contains can be used against you. At issue is whether police can search mobile devices upon arrest without first obtaining a warrant - and whether the data inside, from e-mail to the Internet, are fair game.
For the court, it's the latest in a string of Fourth Amendment search and seizure cases involving society's innovations - from the automobile in the past century to the current alphabet soup of DNA, GPS and mobile apps.
"Every generation has its new technologies that raise novel Fourth Amendment questions," says Orin Kerr, an expert on computer crime law at George Washington University Law School. "Technology changes the facts."
The facts about what police can do when making an arrest have been clear for 40 years: They can search the person being arrested and what's within reach, with an eye toward weapons or evidence that could be destroyed.
"It is settled law that a custodial arrest based on probable cause justifies a full search of an arrestee and any items found on him - including items such as wallets, calendars, address books, pagers and pocket diaries," the Obama administration argues in its petition asking the court to hear United States v. Wurie.
Cellphones and, increasingly, smartphones that mimic computers have clouded those facts. At least six federal or state appellate courts have ruled that they are fair game; at least three others have said search warrants are required.
In the past few weeks, the Supreme Court has been asked to hear both the California and Massachusetts cases, which could help restore clarity in Fourth Amendment search and seizure law. The justices probably will decide this fall whether to hear one or both, and a decision is possible next spring.
'THE REAL CHALLENGE' FOR DECADES
In the Wurie case, the Obama administration urges the court to reverse a 1st Circuit appeals court decision against the police search.
"Over the last decade, cellphones have become ubiquitous in the United States," the Justice Department's petition says. "Inexpensive, disposable phones that are difficult to trace are particularly common in drug-trafficking conspiracies."
In Riley v. California, lawyers for the appealing defendant argue that cellphone searches without a warrant are unreasonable.
"A cellphone nowadays is a portal into our most sensitive information and the most private aspects of our lives," says Jeffrey Fisher, lead attorney for David Riley and co-director of Stanford University's Supreme Court Litigation Clinic. "It's also a device that is the gateway to your office, health records, bank records."
Given the volume of lower court cases and split decisions, it's unlikely the Supreme Court can duck the issue, as several justices publicly wished they could do this year on same-sex marriage - an institution that Justice Samuel Alito noted was "newer than cellphones or the Internet."
In fact, Chief Justice John Roberts and some of his colleagues have said the clash between modern technology and privacy rights is likely to become a dominant legal issue in the future.
"I think that is going to be the real challenge for the next 50 years - how we do adopt old, established rules to new technology," Roberts said during an appearance at Rice University last year. "What does the Fourth Amendment mean when you can, through technology, literally see through walls with heat imaging? I mean, is that a search and a seizure?"
Such cases, Roberts said, "are difficult for us, frankly, because we're not all technologically expert."
CASE LAW IS 'CONFUSING'
The cases coming before the court for possible consideration have little in common beyond cellphones and criminal behavior.
In the Massachusetts case, police opened Wurie's flip-phone to get the number for the repeated incoming calls. The limited search led them to get a search warrant for his apartment, where they seized crack cocaine, marijuana, cash, a firearm and ammunition. Wurie was convicted and sentenced to more than 20 years in prison.
An appeals court panel reversed on two counts, ruling that the cellphone search violated Wurie's constitutional protection against unreasonable search and seizure. The Justice Department asked the Supreme Court to take the case, contending that "police have full authority not only to seize any object they find on an arrestee, but also to search its contents."
In the California case, a routine traffic stop led police to discover Riley's suspended license. They impounded his car, found two guns under the hood and arrested him for concealing weapons. Upon his arrest and again at the police station, they searched his Samsung smartphone, including text messages, photos and video.
Based on that evidence, Riley was convicted and sentenced to at least 15 years in prison; the conviction was upheld at the state appeals court, and the state Supreme Court refused to reconsider it.
Several experts agree with Fisher that the Riley appeal is more pertinent, both because of today's smartphone technology and the broader police searches that could reveal unrelated data. The Pew Research Center estimates that 56% of Americans have a smartphone, 31% seek medical information on their cellphones, and 29% use them for online banking.
"The Fourth Amendment must be sensitive to new technologies enabling police to easily obtain massive amounts of personal information that, at least as a practical matter, would previously have been inaccessible," Fisher argues in his petition.
What both sides agree on is that the high court should tackle the issue. In the Wurie case, judges on both sides of the ruling appealed for Supreme Court intervention.
"The differing standards which the courts have developed provide confusing and often contradictory guidance to law enforcement," said 1st Circuit Court of Appeals Chief Judge Sandra Lynch in her ruling.
FROM QUILL PENS TO E-MAIL
The history of Supreme Court cases on phone technology has been similarly confusing. In 1928, the court said wiretapping didn't require a warrant. By 1967, it said bugging a phone booth certainly did.
Decisions on Fourth Amendment cases also have gone back and forth. The 1969 case Chimel v. California and 1973's U.S. v. Robinson set the standard for what police could search upon an arrest. But in the past few years, courts from California to Texas to Florida have split over the issue of cellphones and digital content.
"The new frontier of Fourth Amendment jurisprudence continues to expand as technology advances," Matthew Orso, a North Carolina attorney, wrote in a 2010 paper on the subject. "This constant expansion creates difficulty for courts in applying decades-old case law to factual scenarios never before considered."
Not far behind the issue of cellphone searches is another legal conundrum: whether police can get the location of cellphone users from service providers without a warrant. Lower courts have split on that issue as well, making a Supreme Court showdown likely in the future.
Increasingly in recent years, the high court has been asked to take on issues so complex or newfangled as to stump the justices, who live in a marble palace of ivory paper and quill pens.
When the justices ruled unanimously this year that human genes cannot be patented, the depth of knowledge required about genetics prompted Justice Antonin Scalia to disassociate himself from parts of the opinion "going into fine details of molecular biology."
"I am unable to affirm those details on my own knowledge or even my own belief," Scalia said.
Computer technology poses other problems for the court. "E-mail is already old-fashioned," Justice Elena Kagan quipped last month, "and the court hasn't gotten to that yet."
A DIGITAL HARE, A LEGAL TORTOISE
Time doesn't stop for the courts to catch up with modern medicine or technological innovation.
"At every turn, as the digital age hare leaps forward, the constitutional jurisprudence lags, like a tortoise, far behind," says Charles MacLean, an assistant professor at Indiana Tech Law School who has written extensively on the issue. "Perhaps the most unfortunate flaw in the tortoise-hare analogy is that constitutional jurisprudence, unlike Aesop's tortoise, never quite seems to catch up."
MacLean has concluded that legislatures, not courts, should address issues of rapidly changing technology - or else, "the risk is that we defer our privacy limits to programmers and marketers."
When it comes to criminal law involving search and seizure, the court since 2001 has been asked to rule on cases involving thermal imaging, global positional systems (GPS) and deoxyribonucleic acid (DNA):
•In Kyllo v. United States, the court ruled 5-4 that police needed a search warrant to use a thermal imaging device that detected heat used to grow marijuana inside a home.
•In U.S. v. Jones, the court ruled unanimously that police could not attach a GPS device to a car without a warrant in order to monitor its movements. Perhaps the die was cast during oral arguments when Roberts confirmed that otherwise, even the justices' cars could be followed.
•In Maryland v. King, the court ruled 5-4 last year that police can swab the cheek of someone arrested for a serious offense to obtain DNA - which then can be matched against databases of unsolved crimes.
Scalia, who wrote the Kyllo and Jones decisions and frequently sides with defendants in Fourth Amendment cases, wrote a scathing dissent in the King case. He warned that in the future, "your DNA can be taken and entered into a national DNA database if you are ever arrested, rightly or wrongly, and for whatever reason."
Some experts warn that if cellphones go the way of cheek swabs, the arrests that follow could lead to embarrassment or legal complications for otherwise law-abiding citizens.
If that happens, "any offense they can arrest you for, they can search the full contents of the phone," says Adam Gershowitz, a professor at William & Mary Law School and an expert on the subject. "I probably do six things that are illegal on my drive to work every day."