I suppose I'm talking to the wrong group of people here, but I decided to write a quick post about how to access anybody's files without needing their username/password for their computer.
It's quite simple:
1) Put in an Ubuntu LiveCD/LiveUSB
2) Boot off it
3) Access their files by going to Places -> X GB/TB Volume
This doesn't work if they have any sort of encryption on their drives or a BIOS password, but otherwise you can do whatever you feel like! So if you have a laptop or a machine that is easily reachable by random people, then you should probably secure your files from something like this if there are things on there that you don't really want people getting to.