As of Android 6.0, you can individually manage app permissions for the PIA App and revoke them selectively.
Step 1: Settings
Open the Android Settings app and tap Apps.
Step 2: Applications
You will see a complete list of apps here. Tap on the app to go to the App info page for that app.
Step 3: Permissions
Scroll down and tap App Permissions. From here to can select any permissions you wish to revoke, if no permissions were granted to the app, this section will be greyed out.