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.
Why not MEGA? While MEGA is free as in beer, the software is proprietary code.
Why not SpiderOak? SpiderOak is proprietary software.
Why not Tarsnap? Tarsnap is partially proprietary and hosts your data on Amazon Web Services.
A mesh network is a decentralized peer-to-peer network, with user-controlled physical links that are usually wireless.
“Mesh networking (topology) is a type of networking where each node must not only capture and disseminate its own data, but also serve as a relay for other nodes, that is, it must collaborate to propagate the data in the network.“
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.
A live distribution like Tails is the fastest and easiest way to a secure operating system. All you have to do is create a bootable CD or USB drive with the files provided and you’re set. Everything else will be preconfigured for you.
A virtual machine (VM) image like Whonix is designed to be run inside of a virtualization package like VirtualBox. VirtualBox can be installed on Windows, Linux, macOS, and Solaris. This means that if you're stuck using Windows or macOS for whatever reason, you can install VirtualBox and use Whonix to increase your privacy and security.
iOS and WP are proprietary operating systems whose source code are not available for auditing by third parties. You should entrust neither your communications nor your data to a black box device.
Installing your own add-ons into Tor Browser is not recommended, as they may bypass Tor or otherwise harm your anonymity and privacy. Check the EFF's Panopticlick to see how trackable your browser configuration is by third parties.
If you're using a Firefox-based browser, you can safeguard your browsing habits and stop advertising companies from tracking you by installing uBlock Origin, Request Policy, and HTTPS Everywhere.
A more advanced alternative to Request Policy would be uMatrix.
Why is Adblock Plus not recommended? Adblock Plus shows “acceptable ads” by default, which works against the purpose of the add-on. Either disable acceptable ads or use uBlock Origin instead.
Use a combination of Tor Browser and a free web browser of your choice to the surf the web.
Try to use Tor Browser as often as possible. Browsing is slower with Tor, but far more secure.
Note: Mozilla Firefox is technically not completely free software, as Mozilla recommends non-free add-ons on their website.
There is also a DuckDuckGo hidden service at 3g2upl4pq6kufc4m.onion for Tor users.
MetaGer is a SaaS by the German non-profit SUMA e.V. that provides you with anonymous meta search results.
Startpage is a SaaS hosted in the USA and the Netherlands that provides you with anonymous Google search and image results through a free proxy.