Many opinions have expressed concern about the possible health effects of GMO food, but few have soundly addressed the extremely serious real problem.
The real problem is monopolization of the nation's (and because of the global economy, much of the world's) food supply.
The GMO seed companies are using their patents to force farmers to use their seeds and to buy new seeds every year.
This is absolutely terrifying.
1. Competition is the fundamental assumption of free-market capitalism. By stifling competition, GMO seed companies prevent the market from working. If you believe in market capitalism and also believe that Monsanto's business practices are OK, you are totally unclear on the concept.
2. "Monocultures" of genetically similar plants are subject to disaster. Ever heard of the Irish Potato Famine? A problem with the GMO seed supply or plants - be it biological, economic or political - could result in a disaster of biblical proportions.
Campaigning against GMOs on the basis of health concerns is ineffective; such problems are difficult to "scientifically prove" (who will pay for the "scientific" study?) and thus can be disputed endlessly.
The solution is political. We must collectively decide that food-supply monopolies are fundamentally unacceptable, striking down the law that allows food to be patented. That won't be easy; monopolists can buy a lot of government.