Three U.S. lawmakers, concerned that Google Inc may have violated U.S. privacy laws, want to know how much personal data the company has gathered through its project to photograph streets across the country and how it plans to use that information.

They also want to know if Google told people they were collecting data as part of the Street View project.

According to one report, Google gathered more than 600 gigabytes of data from Wi-Fi networks in more than 30 countries, California Republican Rep. Joe Barton, California Democrat Henry Waxman and Massachusetts Democrat Edward Markey said in a letter to Google's Chief Executive Eric Schmidt.

Presumably this data could include personal emails, health and financial information, they wrote in the letter, which was dated May 26.

The congressmen cited a Google blog post from earlier in May that said the company had mistakenly collected data from Wi-Fi Internet networks that were not protected by passwords while it was working on Street View.

We are concerned that Google did not disclose until long after the fact that consumers' Internet use was being recorded, analyzed and perhaps profiled, the lawmakers wrote. We are concerned about the completeness and accuracy of Google's public explanations about this matter.

This was a mistake, Google spokeswoman Jill Hazelbaker said in an email. Google did nothing illegal and we look forward to answering questions from these congressional leaders.

Google has sent fleets of cars around the world for several years to take panoramic pictures of streets. People using Google's online atlas for locations and directions in many cases can look at photographs collected by the Street View project and classified by address.

Google uses a combination of data from Wi-Fi, GPS and cell phone towers to determine where smartphone users are so they can be given information based on a specific location.

Barton and Markey, who co-chair the House Privacy Caucus, had previously asked the Federal Trade Commission if Google had broken the law with its data cull.

FTC Chairman Jon Leibowitz has said that his agency would look into it, but he did not say whether there was a formal investigation.

(Reporting by Diane Bartz)

California Eric E. Schmidt Google inc Privacy