@piotrnik, good point, I did not realise it did this. That's a big spanner then. CrayTo5 described the point far moreeloquently than I did, thanks! I guess on your suggestion CrayTo5, it would still be open to anonymous access which is something we're trying to avoid. Apologies, excuse my ignorance. Just thinking out aloud again, hoping to drop a few ideas for the Dev's to think about. I had another idea, which might not be possible as I don't understand completely the communications behind BitTorrent. Say each client generated a complete unique ID upon install, which hashes something unique on the hardware (say MAC?), this ID wouldn't change unlike a dynamic IP address. Then it's with this ID, that is transmitted with the initial connection, you could permit or deny who has access, much like you do with the IP ACL. I hope that makes sense!