The problem with GMOs isn't the GMOs themselves, it's why they've been GM'd. If they've been modified to be "roundup resistant" so they can dump a truckload of glyphosate on them, or something similar to that, that might be a problem.

If I'm buying fresh produce it's not a problem, I can can make double sure to wash it properly. But if it's processed food, I definitely do not trust food manufacturers to get all that shit off the vegetables.

Looking for GMO free canned fruit/vegetables, frozen fruit/vegetables, or anything with fruit/vegetables in it is, in my opinion, a good idea. But a fresh cucumber? Just wash it.