It goes where you go. It knows who you talk to and exactly what you've been up to online. But should you be concerned your cell phone is sharing your personal information? Our Tamara Lindstrom sat down with one expert who says...Yes.

  To view our videos, you need to
enable JavaScript. Learn how.
install Adobe Flash 9 or above. Install now.

Then come back here and refresh the page.

UNITED STATES -- Recent revelations that the iPhone, iPad and Android mobile devices are storing details about where users have been has experts asking questions.

"Cellular phones have always needed location data. That's how calls are routed to the cell phone," said Stephen B. Wicker, professor of electrical and computer engineering at Cornell University. "But this is unusual because it's the manufacturer keeping the location data and the manufacturer, Apple in this case, has not said why they're collecting this data and what they want to do with it."

And worries about what other people could do with it has consumers concerned for their privacy.

"Really the biggest problem is that the file is unencrypted," Wicker said. "So if you have an iPhone, I can take your iPhone and take this file out and I know everywhere you've been for the past six months or year."

But it's not just mobile providers tracking your every move. Those popular cell phone apps may be fun, but they're certainly not free.

"Your personal data means money for some of these companies. And so they will get this data any way they can," Wicker said.

The applications collect information about where you are, who you're talking to, texting and emailing. They use the data not only to enhance the application.

"But at the same time, what's happening of course is that the people who make the application are collecting this data and potentially keeping records so that they can perhaps target advertisements toward you," Wicker said.

That type of direct marketing is big business. According to the Direct Marketing association, it accounts for more than eight percent of the nation's gross domestic product.

Wicker says consumers who want to keep their private lives private should read all disclaimers and opt out of data sharing whenever possible. But when it comes down to it...

"If you don't want to be tracked, don't use a cell phone," Wicker said.

A concession most of us aren't quite ready to make.

Wicker says users should call on elected officials to reform data sharing policies. For more expert advice on how to keep your personal information safe, read that article below.