Virtual Network Computing (VNC) is a desktop sharing system which uses the RFB (Remote FrameBuffer) protocol to remotely control another computer. It transmits the keyboard presses and mouse clicks from one computer to another relaying the screen updates back in the other direction, over a network.
Recently a friend of mine, brought a new Laptop. He installed Red Hat Enterrpise Linux workstation 4.0. However, after installation he realized that he lost all his Mozilla thunderbird emails and Firefox bookmarks, chat client logs and other files.
I told him just copy all old files from /home/$you to a new system /home/$you directory. He was trying some age-old tutorial from net, which explains how to copy files using tar and restore it back to new system. During this procedure, he was messing up with file system permission.