The administrator of the TYPO3 installation should define all necessary countries globally. From that moment, it's possible to select one or more countries that are NOT allowed to sey a certain content element. Like the example above: all users that are NOT from the Netherlands will be able to see that specific content.

When the option 'Grant access to selected countries' was checked this plugin would do just the opposite: ONLY users from the Netherlands would be able to see that specific content.