I monitored my wifi using the freeware Who's on my wifi, that enabled me to capture all their mac addresses which I then used to deny access through my router. I thought it might be a mistake on their part but now I am not so sure. I would like to screw with them a little bit are there any suggestion as to how I might use the information (mac addresses etc.) to yank their chain? Most if not all of their stuff is APPLE . There were 5 devices one with a NetBIOS name of W039524. I am not at all familiar with Apple products.