Wouldn't it technically be possession of stolen "property" to have a dog that belonged to someone else? I, too, would be pissed to find out that a "rescue" had found my dog and not even tried to find me. He is microchipped and ALWAYS wears a collar with tags. If they wanted to, they could find me. If they didn't even try, they stole him. I would pursue legal action if they refused to give him back.