As to GMO itself, this is a tangent but for many people who have reservations about it, it's not about whether GMO has an immediate health impact on the consumer or not, it's about the fact that most GMOs are engineered for pesticide and herbicide resistance allowing vast increases in the amount of these used which run off into rivers and damage ecosystems; it's about companies being able to patent basic food staples and drive out through market abuse non-patented crops leading to monopolies on food production and seed selling; it's about the irreversibility of the introduction of radical changes to the environment that we can't undo. No - putting a gene from caterpillars into a cereal crop that poisons insects that eat it is NOT just a faster version of the plant breeding we've been doing for thousands of years. Finally there's the simple fact that GMOs are used as a patch for our own bad practices, such as Indian farmers being forced to concentrate on growing rice rather than the more balanced variety of crops they used to, meaning they get vitamin deficiencies. And then the same companies that brought about this situation try to present themselves as heroic for engineering a type of rice ("Golden Rice") that contains vitamin D.
Yet whenever GMOs are discussed, I'm immediately faced with people implying anyone against GMOs is an anti-science moron and repeat like zombies phrases like "GMOs haven't been shown to cause health problems".
Rant over.