There were a lot of questions at a Senate Judiciary subcommittee hearing on mobile privacy Tuesday. Representatives from Apple and Google faced tough scrutiny over their privacy and other company policies.

Google’s Alan Davidson, the company’s director of public policy in the Americas, echoed previous company statements that customers have control over whether their data is collected and that the data collected is anonymous.

Apple’s software chief, Guy “Bud” Tribble, emphasized that Apple does not track its users or collect location data from customers without consent. He also noted that an icon appears in the toolbar of Apple devices when location services are in use.

Tribble said that the company has fixed a bug in its latest software update that did record data when users opted out of location services.

But lawmakers weren’t buying it. Subcommittee chairman Sen. Al Franken (D-Minn.) asked if time-stamped location data, even if crowd-sourced, could still be used to trace customer movement. Researcher Ashkan Soltani said that it could be used that way and that claims that the data is anonymous are not completely sincere.

Turning to data-sharing, Franken expressed concerns that current law allows companies to share information with third parties, such as app makers, without disclosing their actions to consumers. He asked whether Google and Apple would require app makers to have a privacy policy in order to submit their programs to the companies’ mobile application stores.

Neither company gave a direct response. Davidson said he would ask Google for a response to that question. Tribble said that he believes privacy must be built into apps to be truly effective, as many people do not read privacy policies.

Subcommittee members asked the companies about other data collection and app curation issues. Sen. Richard Blumenthal (D-Conn.) confronted Davidson over “Spy-Fi”issue, when German authorities found that Google’s Street View cameras were collecting information from wireless networks. Sen. Chuck Schumer (D-N.Y.) revisited his concerns about Apple’s and Google’s reluctance to remove an app that identifies drunk-driving checkpoints.

In the end, few committee members seemed satisfied with the answers given in the hearing, particularly on whether companies were doing enough to protect consumer rights.

“I still have serious doubts that those rights are being respected in law or in practice,” Franken said in closing. “We need to think seriously about how to address this problem and we need to address this problem now.”