I have no problem with genetic modification in and of itself. I think it's a wonderful field of research. The problem comes in with the corporations pushing for genetic modification of everything, and their disregard of both natural products and negative environmental reactions to genetically modified products.
I do not care if you think that there are people who blow the topic out of proportion. Environmentalism does not equate eco-terrorism, even if there are "environmental extremists" who do equate to eco-terrorists.
Firstly, there are cases where genetically modified products simply are not tested enough--and they can lead to negative reactions in different species, which in turn can have a larger impact on the environment.
Secondly, there are cases where genetically modified products are allowed to enter into the ecosystem and cross-pollinate with natural species. This may or may not lead to negative environmental impacts, but regardless there should be safeguards against this, in particular because lawsuits arise involving innocent farmers who have unwittingly produced crops that include such cross-pollination and such.
Thirdly, many genetically modified products produced today have not under gone long-term testing, to deduce the possible effects on the environment and various species over an extended period of time.
And beyond that, there is the obviousness that corporations in control of GM products are often unwieldy entities that simply seek to own everything, and wish to force people to use their products. This fact simply comes back to corporations being large-scale hungry ghosts which can not be sated by their very nature. (Having more equates needing more.)
So it is not as much an issue with genetic modification.. as it is an issue with corporations pushing genetic modification onto people and into the environment, like something of a plague. The plague itself is the corporations, whereas the GM products are simply a symptom, which may or may not even be harmful to the individual.
So the danger, perhaps, is in the mindset of individuals with a desire for much more than they need, coming together in organizations which enhance that desire many-fold.