http://en.wikipedia.org/wiki/Genetic_use_restriction_technol...
Of course, they were called destroyers of the natural order of all that is good when they invented it, so they've vowed not to use it. Instead, they ask anyone buying their seeds to sign a contract agreeing not to save those seeds, which should eliminate the need for the terminator gene. Of course, farmers sign this contract because Monsanto's seeds are a really, really good deal for them! Unfortunately, guys like this want to have their seeds and save them, too, even though they signed a contract saying that they wouldn't. Even more unfortunately, most people who hear about cases like this reactively invent a small-farmer-vs-the-evil-corporation narrative that has nothing to do with reality.