2014-05-28: TrueCrypt currently has security issues and is not recommended.
If you’re running GNU/Linux, dm-crypt with LUKS is the recommended encryption option.
Gentoo GNU/Linux maintains a guide for dm-crypt with LUKS.
Arch GNU/Linux maintains a guide to dm-crypt with LUKS. Also useable for Parabola GNU/Linux.
Switching from a proprietary service like Gmail to one of the more transparently-run email services on PRISM Break is the first step to a secure email account.
The second step is getting you and your contacts to encrypt your plain text messages with PGP encryption. This section contains free email clients that support PGP.
Read the Email Self-Defense guide by the Free Software Foundation to learn how to encrypt your email messages.
Here is a guide by Security In A Box to encrypting your email with Mozilla Thunderbird, GNU Privacy Guard (GPG), and Enigmail.
Find out more about the differences between Mozilla Thunderbird and Icedove.
A beginner’s guide to running your own mail server is available here: “NSA-proof your e-mail in 2 hours”.
Kolab integrates Roundcube into its webclient and offers desktop clients as well. Recent versions also feature a file cloud turning it into a complete solution for personal information management.
What is an MTA?
“Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. An MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol.
The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.”
Apple, Google, and Microsoft are allegedly a part of PRISM. Their proprietary operating systems cannot be trusted to safeguard your personal information from the NSA. We have two free alternatives: GNU/Linux and BSD.
GNU/Linux has a much larger community to help you with the transition. It’s recommended that you begin your explorations by looking for a GNU/Linux distribution that suits your needs. Additionally the Free Software Foundation hosts a list of completely Free distributions.
Debian has a long tradition of software freedom. Contributors have to sign a social contract and adhere to the ethical manifesto. Strict inclusion guidelines make sure that only certified open source software gets packaged in the main repositories.
Fedora is a community edition that serve as the stable basis for enterprise ready GNU/Linux distributions with commercial support. Companies all over the world trust Red Hat Inc. because of their transparency throughout the whole development process.
Canonical’s Ubuntu is not recommended by PRISM Break because it contains Amazon ads and data leaks by default. GNU/Linux distributions based on Ubuntu are also currently not recommended due to several other reasons.
The Etherpad project maintains a list of sites that run Etherpad services. Please only choose from the services that use SSL, and research the site's background before trusting them with your data.