GMOs
And their danger
Allergens
The genetic engineering of crops and livestock includes adding genes from various sources (such as putting a gene from fish into a corn). Manufacturers are not sure as to the dangers of these alterations, and they may pose a risk to those consuming them.
Hurting smaller farmers
Larger corporations continually press against smaller farms owned by them to produce using GMOs and to raise livestock in horrible conditions. They do this by pressing farmers with debt and contracts.
Additionally, GMOs may simply overtake smaller farmer's shares in the market. With higher yield and resistance, it only serves logic this may occur.
Environmental concerns
GMOs are widely considered to be a threat to the surrounding environment of the farm. The use of pesticides and introduction of new genes may upset the delicate balance of the ecosystem. Smaller farms do not introduce these risks and sometimes even aid the environment.
As an example, there was a study conducted around 2000 in which monarch butterflies were fed GM foodstuffs, and another group was fed normal foods. Half of those fed GM foods died while all survived in the other group.
Against nature
Many consider "playing god" by mixing genes and overtaking natural selection is immoral. Or, still, taboos and self inflicted decisions can be impacted by genetic engineering. A vegetarian does not want a strawberry with a horse gene, nor an hindu man with a potato laced with cow genes.
Lax security
The exploding use of GM foods is outpacing the government's ability to monitor and regulate the foods. And, so, many feel the policies are simply too lax.