Yaakov: Well, there are stickers on many organic produce items. Regardless, organic advocates have some complaints about the system, and it may not be perfect (as with hechsherim as we all know), but I’ve never heard that there is a widespread problem with produce being labelled as organic that is not organic.
In the store I normally shop at, the store owners mainly buy from local producers who drive straight there from the farm, and large organic farms in California that distribute their produce across the country. There are not numerous middlemen. The store owners strongly believe in organics, and would not buy from any distribution company if there was the slightest suspicion of that company falsely labeling something organic. They may or may not fear Heaven, but they respect their own newfangled eco-ethics, that’s for sure.