Downloaded more than 23.5 million times, Web of Trust rates websites based on their reputation. While you're browsing, sites with a good reputation will show up with a green circle, bad sites get a red circle, and those in between will look more orange or yellow. Operating System: Windows, Linux, OS X.
This Firefox add-on helps prevent websites from accessing your browsing history. It works with your cookie settings to apply your desired level of privacy. Operating System: Windows, Linux, OS X.
Even when you have your cookies disabled, Flash-enabled sites like YouTube, E-Bay and others can use Flash cookies (also called "SuperCookies") to track your activities. BetterPrivacy automatically disables those cookies. Operating System: Windows, Linux, OS X.
19. AdBlock Plus
Used by more than 12.5 million Firefox users, AdBlock Plus can be configured to block all advertisements or only those originating from domains known to install malware. To use it, you'll also need to subscribe to one of the filters that provide the type of blocking you desire. Operating System: Windows, Linux, OS X.
Instead of re-using the same password over and over, use PasswordMaker to generate completely secure passwords using a one-way hash algorithm. All you need to remember is the name of the site you're visiting and your master password. Operating System: Windows, Linux, OS X.
BleachBit protects your privacy in several ways: it cleans your cache, erases your Internet history, deletes cookies and gets rid of logs, temporary files and other junk you didn't even know your system was storing. It also includes a "shredder" to eliminate completely all traces of files you want to delete. Operating System: Windows, Linux.
If you're getting rid of an old PC or you have other reasons for wanting to destroy all the data on a hard drive, DBAN is for you. It securely deletes all information from all drives it can detect on your system so that those files cannot be recovered. Operating System: OS Independent.
23. Eraser While DBAN erases your entire drive, Eraser securely deletes selected files and folders only. The website suggests it's ideal for eliminating all traces of "passwords, personal information, classified documents from work, financial records, and self-written poems." Operating System: Windows.
If you need a tool like Eraser, but you're running Linux, check out Wipe. It also securely deletes files and folders by writing over the old data several times. Operating System: Linux.
This tool for businesses or other organizations with large networks scans all the Windows systems on a network and identifies which systems contain sensitive data. That information is then sent back via a secure connection to a centralized Web app so that administrators or security consultants can see the results. Operating System: Windows.
Another tool for larger organizations, MyDLP monitors incoming and outgoing traffic on your network looking for sensitive data leaks. It's available in a free community edition or a paid enterprise edition. Operating System: Windows, Linux, VMware.
Used by more than 2.2 million people, AxCrypt calls itself the "leading open source file encryption software for Windows." It integrates seamlessly into the Windows File Explorer—just right-click to encrypt a file and protect it with a password, or double-click to decrypt. Operating System: Windows.
Downloaded nearly twenty million times, this popular encryption tool can protect an entire drive or an entire partition of a drive. And its parallelization and pipelining techniques mean you won't notice any performance delays on your encrypted drive(s). Operating System: Windows.
GnuPG (aka GPG) allows Linux users to sign and encrypt their data or digital communications. This is a command line tool, but several front ends (including some we've featured on this list) are available. Operating System: Linux.
This project ports GPG for Mac users. Note that not all of the features will work with OS X Lion yet. Operating System: OS X.