As you may know, Tails (The Amnesic Incognito Live System) is the open-source, privacy-focused operating system used by Edward Snowden to leak NSA classified documents in the press.
Unlike other operating systems, Tails disguises the footprints of the users and uses some special software to use “keep the privacy private”. Another interesting fact is that the developers of this system are unknown.
Recently, Tails 1.5 has been released, bringing a bunch of new features. It permits the users to “Disable access to the local network in the Tor Browser. You should now use the Unsafe Browser to access the local network.”, uses Tor Browser 5.0 by default, the AppArmor setup has been improved and the network is now properly disabled when MAC address spoofing fails.