Lawmakers considering new privacy laws scolded Google and Apple on Tuesday for not doing enough to guard mobile device users' location data, despite executives' assertions that they do not abuse the information.

I have serious doubts about whether those rights are being respected in law or in practice, Democratic Senator Al Franken said at a hearing of a new subcommittee on privacy, technology and the law.

Senators accused the tech industry of exploiting location data for marketing purposes -- a potentially multibillion-dollar industry -- without getting proper consent from millions of Americans.

Lawmakers did, however, say they would be cautious about drafting privacy rules that could stifle innovation in the space. Mobile device users' personal information helps companies tailor coupons, advertisements and weather information, among many other things.

Don't get me wrong. The existence of this business model is not a bad thing. I love using Google maps for free, Franken said.

The revelation last month that Apple Inc's iPhones collected location data and stored it for up to a year -- even when location software was supposedly turned off -- has prompted renewed scrutiny of the nexus between location and privacy.

Apple has since issued a patch to fix the problem.

Google Inc, a fierce competitor of Apple in mobile computing, has also faced sharp criticism over reports that Android-based phones track the locations of users.

Google said at the hearing that location-sharing on its Android mobile platform was strictly opt-in.

But Google's chief lobbyist Alan Davidson said it does not closely police software applications on its open platform to ensure that app developers have a privacy policy.

Pressed on the issue, Davidson agreed to discuss it with Google executives.

Apple executive Guy Tribble said that Apple does not track users' locations.

But he also quoted from the company's privacy policy, which says that Apple may collect, use and share precise location data. Tribble declined to take questions after the hearing about the discrepancy.

WORKING ON BOUNDARIES

There have been at least four online privacy bills introduced this legislative session. The bills include proposals that companies tell consumers what data is being collected, with whom it is shared and how it is safeguarded.

It is too early to tell which, if any, of the bills might become law.

Senator Sheldon Whitehouse, a Rhode Island Democrat, said he is frustrated that no company is willing to take responsibility for ensuring the safety of customer data -- citing specifically Google's preference for openness, and Internet service providers crawling with malware.

I think we really need to be working on those boundaries. 'As open as possible' is not an adequate standard to this task, he said.

Whitehouse noted that some apps are given away or are sold for very little precisely because app developers plan to collect and sell personal information gathered on their users.

We need to consider a bit more what our model is going to be here. I have not yet heard a model here today that convinces me that it protects the Internet itself and privacy, he added.

(Reporting by Diane Bartz; editing by Andre Grenon and Gerald E. McCormick)