A good round-up, here:
The threat of protests has been most effective when applied to companies with major consumer brands and enough market leverage to dictate what happens for a given crop. The classic case of this phenomenon was how MacDonalds, in three phone calls to major frozen French fry producers, put an end to biotech potatoes in the US and Canada. Potatoes are an extraordinarily difficult crop to improve through breeding because of their complex genetics and vegetative propagation. Biotechnology was a promising way to deliver traits for important pest issues as well as quality and health benefits, and the major potato buyers knew it. However; the risk from brand-damaging protests drove the decision.
You'll want to read the whole thing.