O.K. so I have an Airport Extreme router connected to my Imac. I have it password protected. Yet in finder there's another computer still showing up on my "shared" column that is not one of my computers or devices. What's the best way to handle this? Like I said I have it password protected already and obviously that is not working. Someone said something about doing something that takes a snapshot of current devices connected and having it only allow those. Or is there a way to kick this person off of my network? Any help or advice appreciated.