I am not talking about exposure to the lay public, which is a different problem, but tricks sold on the inside. A magician with low ethics can take a pre-existi

I am not talking about exposure to the lay public, which is a different problem, but tricks sold on the inside. A magician with low ethics can take a pre-existing idea or presentation, tweak it or change the method, and sell it as their own. It's bad, but it is legal. An example of that would be the work Teller had to do to protect his shadow rose effect. Meanwhile, someone wanting to play by the rule might not publish a significant improvement on a 1945 idea that is now out of print, because they could not acquire the rights from the, long deceased, original author.