The innocent bystander problem is one of the key issues in the controversy over the patenting of higher life forms. The problem arises when a patented life form enters adventitiously onto the property of a person who is unaware of its presence. At present it is clear that lack of intent is not a defence to a claim of patent infringement; the questions addressed in this article are whether the Patent Act should be amended to provide an "innocent bystander" defence in such circumstances, and if so, what should be the bounds of such a defence. The argument for amending the Patent Act turns on the issue of innocent bystanders who benefit from their use of the invention. The primary argument in favour of introducing an exemption from patent liability for benefiting bystanders turns on a concern for autonomy of the bystanders, while the mare argument in favour of retaining liability in such circumstances is based on the need to protect patent incentives. The author analyzes the problem of farmer autonomy using economic theory and concludes that while the*e is a legitimate autonomy interest at stake, it is not particularly strong. The article also assesses the treatment of analogous problems in other areas of law, namely the law of tangible property and unjust enrichment, and notes that the law generally dues not protect the same autonomy interest in other contexts. Turning to the problem of patent incentives, the article notes that impairment of patent incentives resulting from truly innocent use is likely to be minimal, but an innocent bystander exemption from liability may nonetheless have significant adverse effects because enforcement difficulties resulting from the need to establish intent may facilitate intentional infringement. The article then describes in detail the structure of an innocent bystander defence that would best balance these competing concerns. It concludes that the net benefits provided by the innocent bystander defence would be minimal and would not justify the additional legal complexity and costs of patent enforcemcnt, which even the best form of the defence would entail.
