• by Wendy Davis  @wendyndavis, February 23, 2012

Google, Apple, Research in Motion and other companies with app marketplaces have promised California Attorney General Kamala Harris that they will require developers to post privacy policies if their apps collect personal data from users.

The mobile platforms also promised in a signed agreement with Harris to offer users an easy way to report developers that violate their privacy policies. Harris and the companies said in a joint statement the deal marks an attempt to "increase consumer privacy protections in the mobile marketplace." App platforms Microsoft, Hewlett-Packard and Amazon also signed.

Harris said in the agreement that she believes mobile app developers must follow California's Online Privacy Protection Act, a 9-year-old law that requires online companies to post privacy policies if they collect "personally identifiable information" about state residents.

Personally identifiable information includes people's names, phone numbers, email address, or any data that can be used to contact or locate people.

The agreement between the platforms and Harris comes as mobile app developers are under fire for gathering and storing information from users without first notifying them. Last week, the Federal Trade Commission said in a report that apps aimed at children weren't providing enough information about their privacy practices.

It also emerged in recent weeks that popular app developers were collecting or storing potentially sensitive information from users. Path and Hipster were caught downloading users' address books without first notifying them. Twitter, meanwhile, reportedly uploaded and stored iPhone users' address books after only obtaining permission to "scan" their contacts; the company intends to revise its language to ask users whether they want to "upload" or "import" their contacts, according to the Los Angeles Times.

A recent survey by the think tank Future of Privacy Forum found that 66% of top free apps had privacy policies, while just 33% of top paid apps had such policies.

The Mobile Marketing Association recently released an apps privacy framework that calls on developers to follow practices that will protect users' privacy.

The privacy company TRUSTe said Thursday that it offers mobile app developers a free service that allows them to generate privacy policies.