That happened to us a very long time ago, we had a Boxer named Duke and we had him tied outside for a while for some air, as he could jump the fence at that time and when we went out to get him, he was gone.
A few days later we left on vacation and my father lived with us and he got a phone call saying they had our dog and how much would we give them to get him back. My father made the mistake of asking who it was and they hung up and we never heard from them again or ever saw Duke again.
As bad as it is today, that happened many years ago when our kids were teenagers. I guess some things and some people never change. It's a sorry day when a person steals someones dog for any reason.
Jackie