Sure have. I keep a list of people not to deal with based on criteria as in the post above. I want my animals going to decent homes. Yes, it means I have a much smaller pool of people to sell to, but I'm okay with that.

Just refused a sale a couple days ago, matter of fact. Had a guy contact me wanting an animal I have up for sale. I always research my buyers, and I found out this guy has a history of scamming people - taking money and never sending anything. He won't be buying from me.