HI guys, I'm just running ubuntu 8.04, everything run perfect, the problem is that I'm sharing an internet cable with my roommate, both of us are connected in the same router no problem with that, but one of this day I opened my network icon and to my surprise !!!! i saw all my roommate home folder files!!!.

I got fu**ing scared, cause if I can see his files, he can see mine too!!!!!!
now my question is:
How can I disable or prevent my roommate to see all my downloaded porno movies and all my projects.
please help me, he's running Ubuntu 8.04 too
Thanks

Set up a host-based firewall?

What's a host-based firewall, and how can I do it?

I just click this: Places>network>mshome>boxin>my roommate name folder and then i can see all his folders and i can open and do everything I click where the icon say JohnBoxin and it mounted in my desktop like another drive (his hard drive or home folder) and from there I can open all his folder like another drive.!!!!!!!!!!!!
PLEASE HELPPPPPPP!!!!!!!!!!!!!!

Don't export any NFS mounts and such, and if you do, require authentication.
You should also tell your roommate that his computer's a whore and giving away his pr0n collection.

Thanks guys, i just found out that I don't have sharing service installed, like NFS or SAMBA,
so I think I'm safe right now, will post later if anything weird happens!

It's a firewall which runs on the box you are trying to protect (as opposed to on the network's gateway). All GNU/Linux distros come with the Netfilter/Iptables firewall, and to configure it you simply need to either execute some iptables commands or run an iptables front-end, such as Firestarter or Guarddog. BTW, Ubuntu 8.04 comes with a text-based front-end called UFW.

That's good news, but keep in mind that none of that is a replacement for having a firewall.