Ethical wall
A firewall is for filtering data going in or out of a network. I remember the term "Chinese wall" being used in news stories related to IBM, but it referred to the wall between the people who read the BIOS listing to figure out what it did and the people who were writing a BIOS to do the same thing on your PC clone, so that's probably what the term "ethical wall" is for.
Biting the hand that feeds IT
