I was not able to test it (for example borrowing a residential IP in a different country) but I suspect they detect OpenVPN via packets inspection, like this example: &quot;Detecting VPN (and its configuration!) and proxy users on the server side&quot; by @ValdikSS <a href="https:&#x2F;&#x2F;medium.com&#x2F;@ValdikSS&#x2F;detecting-vpn-and-its-configuration-and-proxy-users-on-the-server-side-1bcc59742413#.forbbpie6" rel="nofollow">https:&#x2F;&#x2F;medium.com&#x2F;@ValdikSS&#x2F;detecting-vpn-and-its-configura...</a>