California Attorney General Reaches Deal on App Privacy California's attorney general, Kamala D. Harris, said on Wednesday that the state had reached an agreement with Amazon.com, Apple, Google, Hewlett-Packard, Microsoft and Research in Motion to strengthen privacy protections for smartphone owners who download mobile applications. The agreement will force developers to post conspicuous privacy policies detailing what personal information they plan to obtain and how they will use it. It also compels app store providers like Apple and Google to offer ways for users to report apps that do not comply. In a statement, the attorney general's office said developers who did not abide by their own privacy policies would face prosecution under California's Unfair Competition Law and False Advertising Law. "Your personal privacy should not be the cost of using mobile apps, but all too often it is," Ms. Harris said in a statement. The announcement comes on the heels of the news that applications on smartphones routinely transmit people's address book entries and other personal data, often without their knowledge. The practice came under scrutiny last week from members of Congress and the Federal Trade Commission, which regulates the use of consumer data on the Internet. Google, which makes the Android operating system, requires developers to ask users upfront for permission to obtain their personal data, but users often are not told why developers need the data, how they plan to use it or how it will be stored. Likewise, Apple has said it prohibits and rejects any app that collects or transmits personal data without permission. But in practice, developers of some of the most popular applications for the iPhone, iPad and iPod have taken users" contacts and transmitted them without consent. In a statement, Ms. Harris's office said that only 5 percent of mobile apps offer a privacy policy, leaving smartphone owners in the dark about what developers, advertisers and analytic services do with their "location, contacts, identity, messages and photos." Randall Sarafa, a Google spokesman, said in a statement that Google was pleased with the agreement. "From the beginning, Android has had an industry-leading permissions system which informs consumers what data an app can access and requires user approval before installation," the statement said. Coupled with the principles announced by the attorney general, which we expect to complete in the coming weeks, consumers will have even more ways to make informed decisions when it comes to their privacy. Tom Neumayr, an Apple spokesman, would confirm only that Apple was part of the agreement. Ms. Harris's office said it approached companies involved in the app market to discuss privacy in August. It said it would talk to the companies in six months to reassess mobile privacy. In other privacy news, on Thursday the White House will host what it is calling a "privacy event" that is expected to discuss consumer privacy on the Internet. The event is to feature Gene Sperling, director of the National Economic Council; John Bryson, secretary of commerce; and Jon Leibowitz, chairman of the Federal Trade Commission.