Not sure if I've posted this in the right forum so mods please feel free to move if necessary. I should say here at the start that my knowledge of networks and network security is very basic, so please bear with me. Last night as I attempted to shut down my Mac Pro I received a warning message informing me that there were still 8 users connected to this computer. WTF???!!! This is the first time Ive encountered this (sometimes it might say there are still 1 or 2 users connected but this only happens when I forget to shut down my other computers first, hence I assume this message referred to my other computers being connected, but I definitely do not have 8 other computers!). My home network consists of an AirPort Extreme, to which I have my Mac Pro connected by ethernet cable, plus 3 other machines by wifi via WPA2 password (a Mac Mini, MacBook Air and iPhone). In my mind the Mac Pro would have been the least vulnerable and unlikely to be hacked, given that it is NOT connected by wifi, and I dont use it surf the web or download any apps or other files. I do however have enabled File Sharing and Screen Sharing on the MP, plus Allow Incoming Connections for iTunes, so that I can control the MP and access its content using the other computers on my network (using the MPs log-in name and password). As I said above, last night was the first night that set alarm bells off in my mind, but maybe Ive been hacked before and I just didnt notice it. Having limited knowledge of networks and network security, my knee-jerk reaction was to disable Screen Sharing and File Sharing, but this isnt really a practical long-term solution as it means I can no longer access or control the MP through my other machines on my network. I would be extremely grateful for any explanations you could give me on how my MP could have been hacked, and any advice on how to improve my security to reduce the risk of this happening in the future?