Feel free to correct me on this, as I'm likely to be wrong.
Loosely, the way Monsanto's GMO crop system works is, their crops are designed to resist a specific herbicide, which Monsanto also sells. Farmers pay a per-acre licensing fee to use the system, meaning they plant the GMO crops and then bomb their fields with the herbicide to kill everything but the crop, which improves yield.
The fact pattern in these Monsanto lawsuits seems to be that farmers are doing three things: (1) planting Monsanto's GMO crops (intentionally or not), (2) using Monsanto's herbicide to take advantage of the improved yield made possible with the crop, and (3) not paying Monsanto.
It is obviously possible for Monsanto GMO crops to end up in an unsuspecting farmer's field. But it's not possible for a farmer to accidentally use Roundup as an herbicide in that field. If they do that without paying Monsanto, they are trying to get something for nothing. That, to my understanding, is what's motivating the lawsuits.
Where am I wrong on this?