network is a battlefield – different sites try to track you, learn your patterns, or even take over your computer. to the battle one wants to come prepared. full plate armor sounds nice! :)
below is set of nice add-ons to firefox/iceweasel, that helps you to protect your privacy and keep bad sources on the leash. i hope you 'll find these useful as well.
noscript – selective blocker of on page scripts and other plug-ins. if you do not want something to be running, it won't. because of this add-on olone i'm often surprised to see commercials and other crap on web pages i do visit, whenever i happen visit them from some's else computer. ;)
ghostery – privacy control. blocker for tracking services, analyzers and so on. whenever you enter a page it automatically blocks facebook's, goolgle's and others' scripts, that try to collect information about you.
adblock plus – well known plug-in hiding commercials pop-ups away for you.
self destructing cookies – removes cookies when you leave a page or close a browser (configurable on per-domain basis). it's a great balance between usability and privacy.
https-everywhere – enables HTTPS whenever possible, fixes links on HTTPS sites, that point to “regular” HTTP resources, etc.
foxyproxy – per-site proxy configuration tool.
have fun… and some privacy.