Remember that one of the most powerful ways to filter your GPOs so that they only apply to specific users or devices is by using the Security Filtering section of a GPO's properties. Setting up Security Filtering inside the GPMC is quite fast and easy, requiring just a few mouse clicks. We must first remove Authenticated Users from Security Filtering so that the GPO no longer applies to everyone and everything, and instead specify a more selective group or even individual user or computer accounts to which the GPO should apply. In PowerShell, we need to use multiple commands for this to happen.
First, we must remove the Authenticated Users permission that exists by default inside any new GPO:
Set-GPPermissions ...
