Ths isnt very professional http://www.theregister.co.uk/2015/11/30/port_fail_vpn/
Virtual Private Network (VPN) protocols have a design flaw that can be potentially exploited by snoops to identify some users' real IP addresses.
VPN provider Perfect Privacy, which discovered the security weakness, has dubbed it "port fail", and says it affects VPNs based on the IPSec (Internet Protocol security) or PPTP (point-to-point tunnelling protocol) specifications, or using the OpenVPN client software.
BitTorrent users are under particular threat, Perfect Privacy says, because if they use port forwarding as their default torrent client port, they don't need to be tricked into visiting an attacker's web site.
Whilst its probably already been exploited by some group or other at least now the door can be bolted shut to prevent further snooping.