If you are serious about using the internet privately, you should probably be using an anonymous operating system. Listed below are privacy and security enhanced Linux distributions that can allow anonymous web surfing, encryption and advanced security measures. Most of them use the Tor network for anonymous internet connections. They can be run from a removable storage media such as a CD, DVD or USB drive. You can also make a multiboot USB drive to test multiple distributions easily.
TAILS: The Amnesic Incognito Live System
TAILS is based on Debian Linux. It’s a live system, which means it’s a bootable operating system which runs in the computer’s memory, rather than loading from the hard disk drive. It is aimed at preserving your privacy and anonymity. All outgoing connections are routed through the Tor network. Also no trace is left on local storage devices. TAILS comes with bundled software with software like OpenOffice, Claws Mail with OpenPGP and Pidgin.
Privatix Live System
Update: The Privatix distribution has been discontinued.
Privatix Live System is a live OS based on Debian. It is an easy to operate, safe and portable system that can be booted from a CD, a USB Flash Drive or an external hard drive. It ensures your privacy and confidentiality while using the internet and communicating or editing and encrypting sensitive data. Private data and settings, documents, e-mails and PGP-keys are not saved on the your computer instead those are saved on the encrypted USB drive or on the encrypted external hard drive. Privatix Live System provides anonymous web surfing through Tor, Firefox and Torbutton.
Polippix is based on Kubuntu Linux and was created by the IT-Political Association of Denmark as a protest against the anti-terror laws being passed in Denmark. It uses Tor for anonymous Internet surfing, and it has a MAC address changer, GnuPG for encryption.
Ubuntu Privacy Remix (UPR)
Ubuntu Privacy Remix (UPR) runs from a modified Live CD based on Ubuntu Linux. The goal of Ubuntu Privacy Remix is to provide an isolated working environment where sensitive data can be dealt with safely. This is achieved by storing all user data in encrypted form in the removable storage media. UPR was designed to be used for encrypting sensitive data and not for anonymous web surfing. It doesn’t allow network connections.
Liberte Linux is a live Linux distribution based on Gentoo that is secure, lightweight and easy to use. It uses the Tor network for anonymous internet connections, and has features such as persistent storage on a virtual partition and Netfilter IP firewall.
Mandragora is a hardened Linux desktop for use in Digital Forensics-Incident Response (DFIR) and Vulnerability Assessments. Mandragora leverages AppArmor security profiles and auditing, LXC Container Sandboxing (Arkose) and Tor and I2P for enhanced privacy.
Whonix is an anonymous general purpose operating system based on Virtual Box, Debian GNU/Linux and Tor. By Whonix design, IP and DNS leaks are impossible.