HOWTO: Amend your hosts file to block ads (by site)
Note: this is very much a beginner's guide.
Q: What is a HOSTS file / Why might I want to do this?
A: It's explained nicely at http://www.mvps.org/winhelp2002/hosts.htm
Q: But why do this in Ubuntu? My Ubuntu is like a shield of steel!
A: Many reasons. But mainly to save bandwidth by not loading lots of rubbish. For each site listed as 127.0.0.1, content (usually ad banners etc) from that site isn't loaded. In a web browser that picture/frame will 404.
So, how to do it:
The host file in Linux lives at /etc/hosts. We are going to add some lines to it.
***** NOW HEAR THIS *****
A) ***BACK UP*** your /etc/hosts BEFORE YOU START
B) You must APPEND to (not overwrite) the file. You need the stuff that's already in there! That means: paste in the additional lines AFTER what's already in there!
C) I do not recommend doing this if you HOST WEB PAGES from your PC.
End of disclaimer.
1) >>>>>>> BACKUP YOUR HOSTS FILE <<<<<<<<<
$ sudo cp /etc/hosts /etc/hosts.old
2) Download a good hosts file. I recommend the MVPs one:
3) Open your hosts file.
$ sudo gedit /etc/hosts
4) Paste in the contents of hosts.txt into the bottom of /etc/hosts.
5) It should take effect immediately. Close and reload your web browser then try to go to one of the blocked sites. It should 404.