Mobile carriers say customer privacy is their top concern as they expand the products and services they offer.

They say they “anonymize and aggregate” any information they share with third parties about their customers, including location data. That means they remove personally identifying information and combine that data before they pass it on to other companies.

“Protecting customer privacy is part of our handshake that we make with our customers when we offer them products and services,” said Mark Elliott, communications manager for Sprint.

His company does offer “anonymized, aggregated data for things like urban planning and development,” Elliott said.

But when it comes to mobile marketing, he said, “We don't sell any personally identifiable information about our customers, and we do not permit the sharing of customer proprietary network information without an affirmative consent from our customers.”

Debi Lewis, spokesman for Verizon Wireless, said the company updated its privacy policy last September.

She said customers can “opt out” of having their data shared for marketing or advertising. And she said, “Any data that's shared in connection with these initiatives will be anonymous and secure and does not allow for the tracing back to an individual.”

Verizon Wireless plans to use anonymized and aggregate data for marketing reports “to help companies and brands tailor the type of advertising people see on their phones,” Lewis said.

But she said, “We don't have a date certain for that. There's a lot of technical work that needs to go into making that happen.”

In a follow-up email, spokesman Michael Murphy explained that those new advertising initiatives do not use Web surfing or device location information.

“The Verizon Wireless relevant ad program will help brands present relevant ads on customers' mobile devices by using the postal address and other consumer information, such as their device type, demographic and interest information. For instance, if you live near a restaurant, you may see ads for that restaurant.”

Verizon Wireless posts its privacy policy on its website (www22.verizon.com/about/privacy/).

A spokesman for AT&T New England pointed a reporter to the privacy policy on its website (att.com/privacy).

There, the company discloses that it monitors, collects and uses location information about a wireless device that is “generated by its communication with nearby cell towers.”

The company shares “aggregate or anonymous information” with other companies, including “retail, marketing and advertising companies” that “offer products and services that may be of interest to you or to others,” it states.

It also might share data with media research companies; universities, think tanks and others that conduct research; and government and other entities for “municipal planning, transportation planning and navigation services, and emergency and disaster response coordination.”

But AT&T stresses that “respect for individual privacy is fundamental to any decision we make about sharing information with non-AT&T entities,” and it prohibits those entities from using information for “re-identification.”

“We do not sell your personal information to anyone, for any purpose. Period,” it states.

Hanni Fakhoury, a staff attorney with the Electronic Frontier Foundation in San Francisco, said it's not just up to mobile companies to protect your privacy.

“I think people also have to take personal responsibility for themselves too,” he said.

But he said, “I think part of the problem is people gave up their privacy rights for convenience years ago without appreciating what that truly means. And part of that was encouraged by all these companies trying to market all these new features.”

“The problem is we're having that discussion now, after everyone's kind of embraced the share-everything principle,” he said. “The conversation is five or six years too late.”