I think if I was a game company that put out games on old consoles years ago, and I wanted to combat the proliferation of roms, I'd get someone to hack up an emulator thats out of spec for what the system could originally do, and then I'd sell the game with bonus content that relied on that spec. 

 Wouldn't make it past the bean-counters that approve the development expenditures. 

 Probably not. They seem to piss away a lot of money on litigation for something they can't stop, yet they really don't offer a compelling reason to not download a shit load of roms. 

 Agreed. 
Reminds me of the DRM failures in the music industry to try to prevent P2P sharing.