My problem with GMOs is not that the scary stuff that Greenpeace peddles, but the business practices of companies like Monsanto. I also have a problem with the supposedly "pro-science" folks who are anti-GMO labeling on the basis that scare-mongering will keep people from buying GMO-labeled products. I have a Ph.D. in a scientific field and one my absolute most deeply held beliefs is that nothing is more anti-science than withholding information. Don't like what people do with that information? Tough. It's your responsibility as a scientist or pro-science person to educate your audience. Telling people they've got it wrong and don't worry, they should just trust you, and no, we're not going to have a conversation about this is flat out anti-science, period, end of story. If you want people to be OK with GMOs, fine, I agree with you, but it do your job as a scientist, give people complete information, and help them understand the issue instead of making them feel like they're too stupid to understand it.
By the way, one of my other deeply held beliefs is that if you are a scientist and you cannot explain your field to a layperson in a way that they can understand, you probably don't understand your own field very well. In other words, if your excuse is that people are too uneducated to understand, then I think you need to reassess how you're explaining things. You're the educated person, the onus is on you to share your knowledge. If you can't do that, shut up.