But I do recall there was one type of genetically modified corn that was made to produce a specific chemical that caused insects' stomachs to explode. Supposedly it was there to reduce the need for pesticides. I recall thinking to myself, If it does that to insect stomachs, what would it do it animals' stomachs?
The other issue that we haven't fully gotten figured out is cross pollination concerns. Aside from the problem of Monsanto's suicide seeds that grow only once and can't be harvested again accidentally cross pollinating with regular seeds from nearby fields, there is another problem with people becoming legally liable for the actions of bees, butterflies and other pollinators. Some GMO's have unreasonably restrictive licensing. This has resulted in a person's field getting pollinated with by bees who were pollinating GMO plants from a neighboring field now getting sued for having plants they haven't licensed even though did not originally plant that particular variety.