What does Uber know about you?

Andrew Harrer | Bloomberg | Getty Images

No one disputes that Uber is fast, easy and convenient. But when you sign up for the service, you offer the company a lot of data.

Just what does Uber know about you, and how safe should you feel about the privacy of your data?

First, Uber knows who you are and where you're going—essentially an entire travel log.

Regarding what the company does with that information, Uber says it has a firm privacy policy in place, saying that all employees, at every level, are prohibited from accessing a rider's or driver's data.

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Uber says use of its data is allowed only for a limited set of legitimate business purposes." But now there are questions about how airtight that policy really is, and what "legitimate business purposes" really mean.

Ellen Cushing, an editor at San Francisco magazine, says that several Uber employees warned her that Uber executives might look into her travel logs.

Buzzfeed News reported that an Uber executive in New York allegedly tracked one if its reporters without her permission.

"We have not, do not and will not investigate journalists," an Uber spokesperson told CNBC.

Would it be illegal to track users without their knowledge?

That depends, says Gautam Hans of the Center for Democracy & Technology. He says Uber could be in trouble if it uses data for reasons outside of very specific business purposes.

"We understand that Uber needs to know where we are," Hans said. "But the hope is that the company uses that information appropriately."

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Regardless, given the very public outcry over this latest Uber controversy, Hans says state attorneys general as well as the FTC could now be interested in digging deeper into Uber's privacy policy.

The FTC and the California attorney general's office did not immediately respond to CNBC requests for comment.