Patents on objects that have agency such as seeds pose new challenges for governance, raising fundamental questions of control and responsibility. In May 2004 the Supreme Court of Canada found the farmer Percy Schmeiser guilty of infringing the Monsanto patent on genetically modified canola, because he reseeded part of his canola harvest although he knew or ought to have known that it contained seeds of GM canola plants that had blown into his field. In May 2005, a group of organic farmers tried a legal procedure to get certification as a class against two biotechnology corporations Bayer CropScience and Monsanto for polluting their fields with GM canola. At stake are questions on the type of ownership that can be claimed over plants—and whether ownership can be claimed over a plant at the same time that liability for its reproduction is denied. The two court cases I discuss allow us to more closely see how genetically modified canola plants have become objects of contention among Western Canadian farmers, how they transformed the farmers’ daily work and relations between neighbors, and how they increased farmers’ dependency on agro-biotech corporations.