Perhaps Monsanto isn't as bad as they're portrayed here...
That said, I believe the farmer who sold his seeds to the grain elevator was in the wrong, not the farmer (who didn't even know better) who purchased the seeds. This is similar to the file sharer being in the wrong, as opposed to the pirate.
When farmers use Monsanto seeds, they have to realize that they can't redistribute those seeds (or seeds made from those seeds). If this were legal, then Monsanto could be cut out of the picture after the first sale. Farmers could just go to "special" grain elevators who were known to have Monsanto seed progeny and pick up some good cheap stuff. In this case, Monsanto would never be able to recoup the time and billions of dollars spent developing those seeds. It's important to therefore realize that farmers who use Monsanto seeds forfeit their right to distribute seeds to grain elevators; this is their choice.
Farmers choose to use Monsanto seeds. If they still want to distribute seeds to grain elevators, then they can't use Monsanto's products. If it's so crucial that they use Monsanto products, then all hail Monsanto for saving the grain market -- it would have failed (or at least done more poorly) otherwise. And if Monsanto is price gouging, then competitors should have no problem creating alternative products and undercutting them... but they can't because of the aforementioned time and billions spent (which Monsanto needs to recoup or they can't make these "crucial" products).
Although it's easy to paint a David and Goliath portrait here and shed tears for the poor farmers getting sued by a big corporation, right and wrong aren't so black and white here. There's a reason why the laws (made by the people) are defending Monsanto's products here. It's simply not an easy case.