JIM LEHRER: Finally tonight: privacy worries raised by cell phones that can track and share your location.
"NewsHour" correspondent Spencer Michels reports.
SPENCER MICHELS: What happens in Vegas stays in Vegas is no longer necessarily true. These days, cell phones here on the Strip and throughout the country can pinpoint exactly where you are for whoever wants to know, your friends or others.
And they can help you find almost anything you want. That's led to a fast-growing industry for entrepreneurs like Walt Doyle, who developed the Where application for cell phones, especially smartphones. The program can find nearby shows and entertainment, discounts and restaurants.
Let's say I want a kosher and pastrami sandwich, kosher deli. We're on the Strip in Las Vegas. Can you find one with your iPhone there?
WALT DOYLE, CEO, Where, Inc.: With Where? Let me give it a shot, Spencer. I'm going to -- what I'm going to is, I'm just going to type in kosher to where? It came back with some results here for you. We have got a Stage Deli. I assume that's a kosher deli, kosher Chinese restaurant.
SPENCER MICHELS: The phone knows where we are.
WALT DOYLE: Yes. There's the map.
SPENCER MICHELS: There's the map.
WALT DOYLE: Oh, it's right down the Strip. Wow.
SPENCER MICHELS: That's just one of the new uses of cell phones' location technology, which got a big push after 9/11, when carriers were told by the FCC to make sure the location of the phones could be traced.
Today, cell phones and smartphones rely on global positioning system, or GPS, plus a combination of nearby cell towers to zero in on your location.
MAN: We need more people down here.
SPENCER MICHELS: That proved extremely useful in Haiti, when rescuers used cell phone signals to find buried victims of the earthquake.
The geolocation industry is booming. Last year, it took in $34 million. Industry researchers predict phenomenal growth in just five years' time to $4 billion in 2015.
Foursquare is one of a number of apps, including Twitter, Facebook, Gowalla, and Google's Latitude designed to keep people in touch or to meet new people. It's social media with a game and prizes built in.
Dennis Crowley founded Foursquare, which has taken off.
DENNIS CROWLEY, co-founder, Foursquare: We have this process that we call checking in, which is basically you telling Foursquare where you are. So, people check in at bars and restaurants and art galleries and museums and playgrounds and airports.
SPENCER MICHELS: At a location convention in San Jose, 55 attendees were already signed up on Foursquare and could find each other, including Brady Forrest.
BRADY FORREST, O'Reilly Media: I use Foursquare for a couple different reasons. One is just to share my location with my friends. Two is to find out where my friends are, and then three is to help me remember where I have been.
SPENCER MICHELS: It's mostly the tech-savvy younger generation, says founder Crowley, that uses it to connect with friends.
DENNIS CROWLEY: It's definitely our -- our demographic, which I think is like mid-20s to mid-30s or so. And it's primarily based around nightlife. But what we're starting to see is parents with kids checking in at playgrounds to alert other parents about play dates.
SPENCER MICHELS: In fact, parents have been using cell phones with GPS to track their children for several years. Verizon Wireless provides what it calls family locator for $9.99 a month.
But some people say that, in the wrong hands, such devices can facilitate stalking. Kevin Bankston, an attorney with the Electronic Frontier Foundation, finds broadcasting your location troublesome.
KEVIN BANKSTON, attorney, Electronic Frontier Foundation: If you are publishing your location to the world, anyone, including a stalker or a thief or the government or an advertiser or anyone else, can go and look at that information, and hence, the threat.
SPENCER MICHELS: The Web site Please Rob Me, Bankston says, shows in a satirical way that, if someone knows you're at a bar and not at home, they can rob your house. But his concerns over people disclosing their locations go deeper.
KEVIN BANKSTON: How protected is the data that these companies, be it your cell phone company or a location-based service such as a mapping company or a friend-finding service, how long are they keeping this data? And what legal protections apply to this data?
SPENCER MICHELS: It's not always easy to find out what companies do with your data.
Walt Doyle says his company, Where, purges it at this end of every day.
Now, let's suppose I go on to our service, Where, and I -- I look for an AIDS clinic. Can anybody get that information? Can you use that information? Is that a danger for me?
WALT DOYLE: Certainly -- certainly not. I mean, no one can see that information.
Number one, everything that everybody ever does with us is encrypted.
SPENCER MICHELS: Many of the services require the user to choose to share location information. Carriers like Verizon and companies like Google say they protect privacy. But, for many users, that's not a big concern, says Rob Mesirow, who organized this wireless convention for CTIA.
ROB MESIROW, CTIA Wireless: If you don't want them to, you don't opt into it. But, for a lot of the newer generations, really, nobody under the age of 30 has any expectation of privacy.
SPENCER MICHELS: Really? I mean, you're exaggerating, aren't you?
ROB MESIROW: I'm exaggerating, of course, for effect. But, you know, people in their 20s and 30s are putting all this private information up on the Internet. And it's OK. They seem to be OK with it.
SPENCER MICHELS: Eric Blumberg runs an app called Smarter Agent that allows a user to find homes for sale nearby or in other cities.
ERIC BLUMBERG, CEO, Smarter Agent: If you download an application and you're saying, I'm here, find me, you're asking to be found. So, what's the danger?
SPENCER MICHELS: The danger, argues attorney Bankston, is that companies can keep and then divulge location information to the government or to others.
KEVIN BANKSTON: Even if you're just aiming at your friends in the next bar, these -- these companies are obtaining this data. And, so, then the question becomes, what's -- what does the government or a civil litigant have to do if it wants that information?
SPENCER MICHELS: Bankston and others claim that law enforcement and the government have too easy a time getting cell phone information or data stored on servers, an increasing practice.
To remedy that, a coalition has been formed by the Electronic Frontier Foundation, Google, Microsoft, the ACLU, and others to ask for a revision of the 1986 Electronic Communications Privacy Act. The technology has changed so much since then, they argue, that the law is out of date.
KEVIN BANKSTON: What's especially needed in this area is for Congress to step in and to clarify and strengthen the electronic privacy laws that cover this area.
SPENCER MICHELS: The coalition members want to protect digital information from easy government access, without taking away tools the police need to investigate crimes.
They say a judge should have to issue a search warrant based on evidence before tech companies give up location or other information. Meanwhile, entrepreneurs, big and small, continue to introduce new location-based products like this Samsung smartphone with Layar that provides what they call augmented reality, a look at the world that is augmented by computer-generated images.
MAN: So, as you can see the kind of radar icon there, you have all these different people who are tweeting.
SPENCER MICHELS: Such devices will intensify the debate over who should get access to the increasing amount of information available in the digital world.