This is where BetterPrivacy comes in. The extension can be set to automatically delete all Flash cookies every time you exit your browser, or you can manually manage and delete unwanted LSOs one by one so that information can't be accessed or used to track you from site to site.
When you install BetterPrivacy, there's no obvious change to Firefox off the bat. When you close the browser, however, the extension checks for LSOs. If it finds any, you'll see a dialog box asking if you want to delete them. If you hit Cancel, it doesn't do anything; if you hit OK, it deletes them. There's also a checkbox that lets BetterPrivacy automatically delete all LSOs every time after that.
To manage LSOs directly, open BetterPrivacy's preferences in the Tools menu. Here you can remove them one by one or all at once; you can also add specific LSOs to a whitelist to prevent them from being automatically deleted in the future.
One of the more insidious threats bad guys can throw at you is a keylogger, a tiny piece of software that invisibly captures every keystroke you make and sends it back to its home base. Your stream of keystrokes can provide cybercrooks with personal information like your Social Security number or credit card numbers, and of course your log-in information for websites, applications and your computer itself.
QFX Software's KeyScrambler Personal offers a clever way to defeat keyloggers -- as you type, it encrypts the keystrokes at the driver level and then decrypts them in the browser. Any keystroke-logging malware on your computer will capture only the encrypted signal, which it will see as gibberish.
KeyScrambler Personal for Firefox, IE and Flock is free; there are also paid versions -- Pro ($29.99) and Premium ($44.99) -- that extend protection to other browsers, email clients, password managers and many other applications.
Note that KeyScrambler works only with Windows; we don't know of any comparable protection for Mac users. If you know of a similar extension for Macs, please let us know in the article comments.
NoScript is also effective in blocking an emerging form of user tracking called browser fingerprinting. A recent study by the Electronic Frontier Foundation (EFF) showed that even without cookies or malware, websites can pull enough information about a user from the browser itself to build up a profile that can be used to track the user from site to site. The EFF singled out NoScript as an effective safeguard against this kind of tracking.
Since so much of the Web relies for basic functionality on the scripting languages that NoScript blocks, an Options button at the bottom of the browser window pops up a menu with options that you can use to temporarily or permanently allow scripts on sites you trust.