Firefox Plugins

Google Sharing
GoogleSharing is a system that mixes the requests of many different users together, such that Google is not capable of telling what is coming from whom. GoogleSharing aims to do a few very specific things:
1. Provide a system that will prevent Google from collecting information about you from services which don’t require a login.
2. Make this system completely transparent to the user. No special websites, no change to your work flow.
3. Leave your non-Google traffic completely untouched, unredirected, and unaffected.
https://we.riseup.net/assets/75287/googlesharing-0.23-riseup.xpi
https://addons.mozilla.org/en-US/firefox/addon/googlesharing/ (official version doesn’t work on up-to-date firefox, as of January 2012)

Beef Taco (Targeted Advertising Cookie Opt-Out)
Sets permanent opt-out cookies to stop behavioral advertising for 100+ different advertising networks, including Google, Yahoo, Microsoft, all members of the Network Advertising Initiative, and many other companies.
https://addons.mozilla.org/en-US/firefox/addon/beef-taco-targeted-advertising/

Better Privacy
Flash-cookies (Local Shared Objects, LSO) are pieces of information placed on your computer by a Flash plug-in. Those Super-Cookies are placed in central system folders. They are frequently used like standard browser cookies. Although their thread potential is much higher as of conventional cookies, only few users began to take notice of them. BetterPrivacy allows to list and manage Flash-cookies, e.g. to remove those objects automatically on browser start, browser exit or by a configurable timer function while certain desired Flash cookies can be excluded from automatic deletion. So this extension becomes sort of “install and forget add-on”. Usually automatic deletion is safe (no negative impact on your browsing), especially if the deletion timer is activated. The timer can delay automatic deletion for new or modified Flash-cookies which might be in use. It also allows to delete those objects immediately if desired. Users who wish to to manage all Flash-cookies manually can disable the automatic functions or exclude certain Flash-cookies from automatic deletion.

HTTPS Everywhere
HTTPS Everywhere is a Firefox extension produced as a collaboration between The Tor Project and the Electronic Frontier Foundation. It encrypts your communications with a number of major websites. Many sites on the web offer some limited support for encryption over HTTPS, but make it difficult to use. For instance, they may default to unencrypted HTTP, or fill encrypted pages with links that go back to the unencrypted site. The HTTPS Everywhere extension fixes these problems by rewriting all requests to these sites to HTTPS. https://www.eff.org/https-everywhere

Convergence
Convergence is a secure replacement for the Certificate Authority System. Rather than employing a traditionally hard-coded list of immutable CAs, Convergence allows you to configure a dynamic set of Notaries which use network perspective to validate your communication.
http://convergence.io/

To Be Tested

Disconnect
If you’re a typical web user, you’re unintentionally sending your browsing history with your name and other personal information to third parties whenever you’re online. Disconnect lets you:
Disable tracking by third parties like Digg, Facebook, Google, Twitter, and Yahoo, without requiring any setup or significantly degrading the usability of the web.
See how many resource requests are blocked, in real time.
Easily unblock services, by clicking the toolbar button then services (and reloading current pages) — e.g., so you can play games on Facebook.
https://addons.mozilla.org/en-US/firefox/addon/disconnect/

NoScript
It allows JavaScript, Java and other executable content to run only from trusted domains of your choice, e.g. your home-banking web site, guarding your
“trust boundaries” against cross-site scripting attacks (XSS), cross-zone DNS rebinding / CSRF attacks (router hacking), and Clickjacking attempts.
https://addons.mozilla.org/en-US/firefox/addon/noscript/

RequestPolicy
RequestPolicy is an extension that improves the privacy and security of your browsing by giving you control over when cross-site requests are allowed by webpages you visit. Cross-site requests are requests that your browser is told to make by a website you are visiting to a completely different website. Though usually legitimate requests, they often result in advertising companies and other websites knowing your browsing habits, including specific pages you view throughout the day. Among the attacks that cross-site requests are used in, they are particularly dangerous with Cross-Site Request Forgery (CSRF) attacks where your browser is told to make a request to another website and that other website thinks you (the person) meant to make the request. With RequestPolicy, the default for any cross-site request is to deny it. Users are notified when requests on the current page have been blocked (the status bar flag icon at the bottom right of your browser turns red). Clicking on this status bar flag icon gives you a menu where you can view and modify which requests are blocked and allowed. You can whitelist requests you approve of by origin site, destination site, or specific origin-to-destination.
https://addons.mozilla.org/en-US/firefox/addon/requestpolicy/

CsFire
When a website makes requests to another site, all kinds of malicious effects can occur. For instance, the information included in the request can be used to track the sites you visit. The request can also trigger certain undesired actions, an attack which is called Cross-Site Request Forgery (CSRF). CsFire protects you against malicious cross-domain requests, by rendering them harmless. This means that CsFire will remove authentication information (cookies and authentication headers), which ensures that a cross-domain request can not have harmful or undesired side-effects.
https://addons.mozilla.org/en-US/firefox/addon/csfire/

Ghostery
Ghostery allows you to block scripts from companies that you don’t trust, delete local shared objects, and even block images and iframes.
https://addons.mozilla.org/en-US/firefox/addon/ghostery/

TrackerBlock
Complete control over online tracking using multiple methods, including cookie blocking, persistent opt-out cookies, Flash and HTML5 control, and Do Not Track signals.
https://addons.mozilla.org/en-US/firefox/addon/trackerblock/