Privacy is about user information. This can be data like names, addresses, emails but also indirect data like a user’s browsing habits, past purchases at an online store or a search history. Companies use the information for instance to track a user on the Internet to display targeted advertisements. But privacy can also be abused, say by malicious users who hacked into a company database to get all user names and emails, to communicate with those others afterwards (phishing comes to mind). Privacy can also be a local matter. A wife who does not want her husband to find out what she is doing on the Internet, parents who do not want their kids to see some of the sites they have been visiting.

Privacy add-ons cannot protect from all threats related to privacy. They cannot be used for example to delete your shopping history at Amazon or eBay. They can however protect you from the majority of dangers.

Firefox Privacy Preferences

Firefox has a few privacy related options that can be customized easily to improve privacy immediately. You find the settings by clicking on Tools > Options, or Firefox > Options in the menu. Switch to the privacy tab. The default setting here is to remember history. If you switch that to custom settings for history you get several new configuration options.

All of those settings are about local information, like the download or browsing history. If you do not want the browser to record the information, uncheck the box. You can also configure Firefox to clear the history on exit, which would mean that you have access to the history during sessions, but not after the browser gets closed down.

Helpful articles:

How To Clear A Browser Cache
How To Delete Cookies On A Computer
Configure Firefox To Delete All Cookies On Exit But Select Ones

Firefox Privacy Add-ons

Firefox offers many privacy related add-ons for download. This list includes only add-ons that are working under Firefox 4. The majority will work under Firefox 3 as well, I try to mention it if an add-on does not.

Email

TrashMail.net – Anti-Spam

Create a temporary email address for immediate use on the Internet. Handy for signing up on websites that you do not trust to keep your email address confidential, or submitting a comment on a site.

Alternatives are Less Spam, please, Bloody Vikings and Spamadvert.

Forms

Form History Control

Firefox records by default what a user enters into forms on web pages. While it is possible to delete all form history at once via the clear browsing data tool, it is not comfortable to delete select form entries. You can visit the form again, enter the first characters of the text you have entered, hover over the suggestion that pops up with your mouse and press the delete key on your keyboard to delete it.

Form History Control simplifies the process. It displays all form data that is currently stored in the browser. You can use it to view, edit and delete entries easily.

FormFox

Displays the form action on mouse over. The form action determines to which website or server the entered data is submitted to. This is sometimes used in malicious ways, for instance on phishing sites.

Tracking

AdBlock Plus

An ad blocking extension that can be extended with subscriptions to include privacy related protections to the web browser.

Better Privacy

Protects a user’s privacy by offering better Flash Cookie (LSO) handling in Firefox. Can remove Flash cookies automatically on exit, something that will be supported by Firefox soon by default.

CsFire

Protects against malicious cross-domain requests, including Cross-Site Request Forgery.

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.

Ghostery

Displays information about page elements used to track website visitors. This includes tracking pixels and scripts such as Google Analytics or Facebook.

PrivacySuite

A collection of tools that improve a user’s privacy on the web. This includes email and phone protection, blocking of online tracking, cookie controlling and privacy alerts that display trackers that are active on a site.

Selective Cookies Delete

Delete cookies on-demand and based on pre-defined rules. You can use the add-on to clean up cookies from specific sites, or all cookies but those from some websites.

A similar extension is Cookie Whitelist.

Tracker Block

Block companies from tracking you through cookies and Flash cookies. Blocks more than 300 different ad companies from tracking users on the Internet.

TrackMeNot

Uses random search queries to protect against search data profiling.

Misc privacy extensions

Boss Key and Buttons

A boss key to minimize the browser immediately.

Certificate Patrol

Displays certificate updates to give the user a tool at hand to verify the legitimacy of updated certificates.

HTTPS Everywhere

Can be used to force HTTPS connections to select websites, for instance to always connect via HTTPS to your email provider, favorite websites or financial sites.

HTTPS Finder

Informs the user if an https version of the website is available. Can create rules for HTTPS Everywhere.

Long URL Please

Turns shortened urls into their destinations so that it is possible to see the link target right on the site the short url was posted on.

Perspectives

Validates Firefox HTTPS security errors by querying select Network Notaries.

Stealthy

A web proxy add-on for Firefox. Use proxy servers to hide your real IP address or visit websites that would be blocked otherwise.

Proxilla Glype Proxy Client is an alternative, as is Phzilla and Go2 Proxy

Closing Words

Firefox users can improve their privacy with add-ons tremendously. The right selection depends entirely on their web use. Do you think an add-on is missing from the list? Let everyone know in the comments. Post your privacy tips there as well.

It is important to note that private browsing is only helpful to avoid records of browsing sessions on the computer used. It does not hide the user from the Internet Provider or websites that they visit.

Private Browsing can be enabled in the Firefox Tool menu. It will display a popup that contains information that private browsing mode will be started and all currently open tabs will be saved to be reopened after the private browsing session ends.

Firefox will not record browsing history, search history, download history, web form history, cookies and temporary Internet files. Bookmarks as well as downloads on the other hand will be retained in private browsing mode.

Firefox will add the (private browsing) string to the title which is a indicator for anyone that Private Browsing is enabled. Private Browsing can be disabled from the Tools menu again by selecting the same menu entry that activated it.

Users who regularly clear data when closing Firefox might wonder why they should be using the Private Browsing mode at all. The main difference between clearing data when closing the browser and using the Private Browsing mode is that the Private Browsing mode will never store data on the hard drive. This might however happen when cleaning Firefox data by closing the browser. First, data could be recovered and second it will still be there if Firefox closes unexpectedly.