Six of the biggest mobile application providers, including Google, Apple, and Microsoft have agreed to improve privacy protections for their customers.
HP, Research In Motion (RIM) and Amazon also signed the agreement, which came after pressure from the US justice system and California's attorney general, Kamala Harris.
"Your personal privacy should not be the cost of using mobile apps, but all too often it is," said Harris.
"This agreement strengthens the privacy protections of California consumers and of millions of people around the globe who use mobile apps."
Harris added that privacy policies will allow users to stay informed over who has access to their personal data and how it is used.
The six companies have committed to educating application developers about their obligations to respect consumers.
If the companies fail to adhere to the agreement, the Attorney General said they can be prosecuted under California's Unfair Competition Law and False Advertising Law.
Users will soon be given tools to report non-compliant applications too.
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