my only concern with you giving away the dog on CL is that once you have someone take him, and if he would bite/attack new owner or someone else then maybe they can come back on you.. you may just be putting yourself into a situation you don't need or want. sorta like you are now, but i would get sheriff to get dog. and deal with his owner.. again is there an ordinance in your area? plus like someone said real owner may turn you in for giving away his dog..