I am writing a simple game for which I would like to have sound effects. I have been considering purchasing some of the sound effects online, but have the issue that as far as I am aware, anyone could buy my game, go into dev mode, and get those sound effects. This would go against the licensing terms of company that sells me the sounds. Is there any way around this? I know that all code is available for people to view, but is there any way to protect media (audio, and I guess images too)?

If not, as I understand things, this would mean that any sound or graphic you develop with your application will be free for anyone to take, once they get your app. Which also means, any sound or graphic that you get online has to be public domain already. Is this all correct?