When you "steal" a secret, it's not longer a secret. When you "steal" credit, the original thinker no longer gets credit. In both cases, the thing itself was destroyed: in the former, the secret is no longer a secret at all and in the latter the boss will no longer be considered the mastermind behind the idea. When you "pirate" something the original copy remains and the creator retains it and the rights to sell copies of it and will still benefit from selling copies. It's not theft.