Wow! Antique-shop.com forums are in the big #1 spot on Google for the search term "antique shop forum", for 4 years running!Thanks to YOU.
He can't use it without permission he is infringing on your property. I work for a catalog company and we find people on Ebay using our pictures. We write to them and tell them to take it down that we own the photography. If they don't take it down you can sue them and win. That being said not worth the cost of suing but a nice letter to them usually does it.
Not always. If you upload it to a public site on someone else site it is ok but if they take it from your own site completely different. At least that is what our lawyers said.