• by Wendy Davis  @wendyndavis, July 14, 2009

Yahoo Tuesday announced that has developed a feature that will allow users to opt out of behavioral targeting on mobile devices.

"We believe the mobile experience should offer the same privacy protections consumers expect to find on the PC," Yahoo said in a blog post announcing the feature. "Furthermore, management of privacy protections should be available via any mobile device, whether that's an iPhone or a Blackberry."

Many companies that track people's Web activity on PCs and send them ads notify users about the practice and allow them to opt out. But it's still unusual for behavioral targeting companies in the mobile space to let people opt out. At least a dozen companies say they offer some form of mobile behavioral targeting. But only two appear to allow users to opt out, according to Jules Polonetsky, co-chair and director of the think tank Future of Privacy Forum.

"Yahoo is being nimble in moving in front of this, and we're urging others to move quickly," Polonetsky says.

Some consumer advocates have said that concerns about privacy on mobile devices are even greater than on PCs, because mobile devices tend to be used by just one person. Additionally, the ability to identify specific devices, and to pinpoint cell phone users via geo-location data raises an additional layer of privacy concerns.