Sega tried this to prevent third party games from running. It didn't work: because their string was required for functionality, it wasn't protected by copyright

Sega tried this to prevent third party games from running. It didn't work: because their string was required for functionality, it wasn't protected by copyright. See http://en.wikipedia.org/wiki/Sega_v._Accolade http://en.wikipedia.org/wiki/Sega_v._Accolade for details.