Farmers' markets vs "farmers" markets

If you go to the farmers' market circuit in the GTA, you may know what I'm talking about.

A month ago, I was at Sherway Gardens' farmers market. I'd say that it was 50% artisinal goods and 50% food picked up from the Food Terminal. Some products had PLU stickers on them. Others had the FOODLANDS boxes stacked behind them.

I'm wondering how prevalent this is at the various farmers' markets? How are you assured that you're getting true farmers' produce and not something a vendor picked up at the Food Terminal?