We know Monsanto sues farmers for GMO's

I absolutely think farmers should be able to sue Monsanto for cross-pollination.
I am dumfounded and thunderstruck - but then again, this is corrupt corporate America - that Monsanto can sue farmers.

But what would happen if they sue the offending farmer rather than Monsanto? Ultimately, it's the farmer that puts the seed into the ground. Evils of Monsanto aside, shouldn't the farmer planting this stuff bear some culpability?

I have no clue and would be interested in hearing from some persons with a legal background.

Farmer A plants open pollinated corn in his fields. 1 mile down the road, Farmer B plants genetic corn that is covered by a patent. Corn is pollinated by wind. Farmer A's crop becomes cross pollinated by Farmer B's crop thereby putting his crop under the legal restrictions of the patent which wasn't Farmer A's wish.

Why isn't there any legal liability for Farmer B for not preventing his crop from contaminating Farmer A's crop? I've never understood that. There are plenty of legal ramifications for Farmer A should his corn be sold or he reuses the seed. Why isn't there any legal liability for Farmer B for letting his patented seed contaminate the crop of Farmer A in the first place?

I hope some of the legal eagles on DU chime in. Aside from the fact that no small farmer can challenge the legal muscle of Monsanto, it just seems that if you let your patented crops contaminate mine, I should have the ability to seek legal redress.