As I have already said, that does not happen. In countries without mandatory labeling of ingredients companies *do not* voluntarily provide the information. The government is not doing the informing, it is merely requiring that businesses tell the truth about what they're selling. That libertarians are so much against this is the reason why libertarians so often come across as extremist zealots to the majority of people. Some people don't care whether they're eating GMO food and they will keep eating it whether it is labeled as such or not. The reason Monsanto and other agribusiness corporations fight tooth and nail against GMO labeling laws is not because it costs any significant amount to add a little extra ink to the label, but because they know a lot of people won't buy their product if they know what's in it. So you are taking the side of those who want to lie to their customers.