I am new so this might already exist but I believe it would be a good idea to make a list of puzzles that are commonly knocked off but for each puzzle, include websites that offer the real and legal version of the puzzle. This would also allow people to check if the puzzle they are thinking of buying is a KO without breaking the KO website policy.
It is a great idea and has been suggested before (here
and my response here
), but since that time I have been a bit busy and have not yet created it. It will require some time to generate the proper list with appropriate links and information. But I think I have a way to get help with that even if I don't have the time myself.