Owners fear that by disabling the app rather than uninstalling it, Facebook might still be able to track them and share their data without permission. There is a movement trying to get people to delete Facebook in protest of its privacy and security issues. A Facebook spokesperson told Bloomberg that disabling the app on Samsung devices makes the app behave as if it is deleted. If true, that certainly brings up the question if disabling makes the app act as if it's deleted, why can't users remove the app if they want?
Facebook notes that whether the app can be deleted or disabled depends on deals it has made with smartphone makers. The social network has declined to say what smartphone brands it has deals in place with that prevent the app from being removed. It has stated that the deals vary by region and type. Preinstalling the app is meant to give the users the best experience right out of the box according to Facebook.
Some privacy advocates are calling for Facebook to file public documents on deals of this sort and to turn over records proving the app collects no data when it is disabled. Some Samsung device owners feel strongly enough about the inability to uninstall Facebook and the privacy concerns that have expressed a desire to switch to other device brands in the future. Apple is one of the few brands that doesn't preinstall any third party apps on new smartphones.