Google has removed an experimental privacy feature from its Android mobile software that allowed users to block apps from collecting personal information such as address book data and a user's location.
The change means owners of smartphones using Android 4.4.2 must provide access to their personal data in order to use certain apps.
A spokesman said the feature had been included by accident in Android 4.3, the version released last year.
Peter Eckersley, technology projects director at the Electronic Frontier Foundation, said the explanation was suspicious.
"[We] do not think that it in any way justifies removing the feature rather than improving it," he said in a blog post.
Android users who wish to retain the privacy controls by not upgrading to Android 4.4.2 could be vulnerable to security risks, Eckersley said.
"For the time being, users will need to chose between either privacy or security on the Android devices, but not both."
Many third-party apps for Android devices require access to personal information that does not always have an obvious connection to the app's functionality, such as phone call information and location data.
The privacy feature allowed users to pick and choose which personal data a third-party app can collect. Users had to install third-party Apps Ops Launcher software in order to access the hidden privacy controls.