Apple and Google were put to on the hot seat again at a hearing before the Consumer Protection, Product Safety and Insurance Subcommittee on consumer privacy and protection in the mobile marketplace. The Thursday hearing was chaired by John D. (Jay) Rockefeller IV (D-W. Virginia).

Google and Apple recently testified on privacy before a Senate Judiciary Committee led by Sen. Al Franken (D-Minn.)

Prior to this latest hearing, Rockefeller asked executives from Apple, Google and the Association for Competitive Technology (ACT) to show whether the applications running on their mobile platforms are in compliance with children's online privacy law.

"I am concerned that some applications running on today's mobile platforms may be violating laws that are intended to protect children. My hope is that Apple, Google and the ACT can shed light on mobile app practices so that we can make sure children are protected," Chairman Rockefeller wrote in a press release.

Rockefeller was referencing with his request a law known as the Children's Online Privacy Protection Act (COPPA), which prohibits certain online companies from collecting personal information from children 12 years old or younger without express consent from their parents, disclosure of use and requires companies to provide parents access to the information they collect.

The hearing started out with some statements from both Senators Rockefeller and John Kerry (D-Mass.) that stressed the delicacy of trying to regulate privacy on mobile devices and in applications without stifling innovation.

"While today's hearing is principally about mobile phones and the apps that come on them, it's important to put the mobile phone and apps in the larger context of privacy itself," Kerry said, but added that "the mapping of consumer's movement without consent is unacceptable."

Kerry said he rejects the idea that privacy protection is the enemy of innovation. "It absolutely doesn't have to be and isn't," he said.

While the hearing seemed aimed at more specific issues around protecting privacy on the mobile, they didn't go too far afield from those issues covered during Senator Franken's hearings before the Senate Judiciary committee last week.

The panels, which included Apple, Google, Facebook and the Federal Trade Commission (FTC), among others, focused on how applications track users, as well as investigating ways to better protect children on the mobile Web.

David Vladick, director of the FTC's Bureau of Consumer Protection, outlined what appear to be emerging as the generally agreed upon pillars of the privacy debate. He said that any regulatory efforts have to be aimed at ensuring that consumers know what data is being taken, for what purpose and by whom.

Currently that doesn't appear to be the case, and consumers are increasingly wary of sharing their information, whether voluntarily or otherwise.

Amy Guggenheim Shenkan, president and chief operating officer for Common Sense Media, a consumer protection agency, said that 85 percent of parents polled said they are more concerned about privacy than they were five years ago.

Both Apple and Google reiterated their comments from last week regarding how their devices obtain location, save and use location data. Google argued that its devices alert users to what information any app is using before that app is downloaded. Apple again asserted that the iPhone never collected a user's location data but rather the location of nearby cell towers and Wi-Fi hotspots. Apple also said that it rolled out a firmware update that fixed a bug that caused certain location settings to not work.

On the whole, all of the panelists agreed that privacy needs to be a focus for both regulatory agencies and the technology companies themselves. More transparent, clear and concise privacy agreements were at the top of the list of things that would go a long way towards improving the situation.

Morgan Reed, executive director of ACT, said that developing privacy agreements that hold up in court and satisfy lawyers is challenging on the mobile side of things because these agreements have to be displayed on such a small screen.