San Francisco, Dec 17 : Apple has hit back at Facebook over its upcoming iOS privacy charges, saying that the tech giant stands up for its users. Reacting to full-page newspaper ads by Facebook that criticised Apple for its privacy changes, Apple said that users should know when their data is being collected. "We believe that this is a simple matter of standing up for our users. Users should know when their data is being collected and shared across other apps and websites Â? and they should have the choice to allow that or not," Apple said in a statement late on Wednesday. "App Tracking Transparency in iOS 14 does not require Facebook to change its approach to tracking users and creating targeted advertising, it simply requires they give users a choice". Facebook had earlier criticised Apple's plan to bring iOS 14 privacy changes that would make it tough to target users with ads. Apple postponed the full enforcement of privacy practices in iOS 14 until next year after Facebook went out in public against those changes. The feature would require app developers to request users' permission to track them across apps for advertising purposes. Facebook had complained about the feature, saying it would impact its ad business. Facebook acknowledged that full enforcement of these changes may lead to huge decline in its Audience Network advertising business. Facebook Audience Network is an in-app advertising network for mobile apps. Apple had accused Facebook of a "disregard for user privacy" while responding to similar claims from the social network last month. /IANS