Apple says it will require developers to obtain approval from users before installing applications that access contact list data. The company issued its policy change after a clamor erupted when it was revealed that sites such as Path, Twitter, Foursquare and Yelp had accessed, transmitted and stored users' data without their permission. The controversy prompted Rep. Henry Waxman, D-Calif., to ask Apple to explain its policy in a seeming threat to whisk the company before a House subcommittee. Developers said they would have little trouble adjusting their apps to meet the new rules. Google responded by saying that Android users have to opt in before Android apps share data with developers.