Fen - I know you're technically correct. Images can't be protected from someone with the technical knowledge and know-how to do this.
Then again, that's like telling me that I can't make my house safe. Doesn't mean that I'm not going to lock it up when I leave. Honestly, if you were to ask me to go into my browser cache and grab a Flash file, de-compile it and lift out the image resources, I'd probably give you a funny look...
...these procedures make sure to keep the honest (or relatively honest) people that way.