I got mugged by a very friendly, emaciated red Siberian in my college parking lot last winter. She hoped right into my car and we drove down to my friends pet shop, she didn't know the dog. So I drove her over to the SPCA and we scanned her for a chip, nada. Shelter supervisor said that they knew her and had been out to see her on a complaint before BUT if I left her there the only thing they could do is charge for boarding, not for the running at large or lack of license or (most likely) lack of rabies vaccination. If I took her home and called bylaw enforcement they would pick her up, bring her right back to the SPCA and write the owners up for anything they could think of (running at large, no license, no vaccinations and hopefully make the bill so large that the owners would turn the dog over to the SPCA. So she came home with me for about an hour before she went for another car ride to a nice place with heated floors and food, instead of back to the chain in the backyard.