Our farmer's markets suffer from customers that graze on the food before they buy it and destroy the product in the bins while looking for the perfect version for themselves. They are also under the strange impression that it's just and outdoor Safeway and expect the same things.
Morons.
But we don't get many con artist cheapskates beyond the "I pay cash, you not charge tax." ethnic cliche.
Just about everything is on debit card transaction.