Being from Africa I can tell you that the Patents linked with GMOs are really bad. The subsistence farmers depend on part of their harvest for the next crop. GMOs owned by corporations have patents that if introduced or even an adjacent field cross-pollinates with your crop you are in violation of several patents. So every year you are forced to buy new seeds from the Corporation. I hope this gives you a bit of insight as to how subsistence farming is hurt by these types of seeds.
Maybe opensource type GMO is in order? Who knows.
What happens to farmers who don't buy new seeds and just reuse seeds from their current crop, licensed or otherwise? Are there examples of them being pursued by patent lawyers?