Personally, I'm not terribly interested in preventing carting. I'm not very fond of repro makers, but they aren't worth losing sleep over. One idea I've seen tossed around recently is adding a message to the game to the effect of "If you payed for this, you've been screwed," but that's so easy to remove, it almost seems pointless. Maybe it will deter carters with a hint of decency. Who knows? What's more important to me is that if somebody wants to play this on a flash cart or even wants to cart it for personal use, it would be a shame to screw that up.