From the moment you boot up, your computer leaves footprints. Websites leave tracking cookies, following you from page to page and session to session, alongside the usual traces left by your IP address. Persistent logins from Google and Facebook tie each site visit to your offline identity. If anyone really wants to go after you, they can also make a direct attack, targeting malware to track your movements in the background. With the right tools, a computer is an open book.

Not this computer, though. It's running Tails, an open-source operating system designed to leave as little trace as possible, launching version 1.0 today after more than five years of open development. It's an amnesiac system, which means it's completely fresh every time you boot up. There are no save files, no new programs, and most importantly, it becomes a blank slate the moment you shut down. It's the digital equivalent of buying a new computer for a single session and tossing it into the river once you're done.

That trick has earned Tails a lot of attention. It’s already standard software at Glenn Greenwald’s First Look Media, where he’s called it “vital to my ability to work securely on the NSA story.” Tor researcher Jacob Appelbaum praised the project onstage at this year's Chaos Communications Congress, and in March Tails received a $50,000 grant to keep the project going. Nearly 8,500 computers booted up with Tails on a given day in March, 500 more than the month before. Those are surprisingly high numbers for a project that’s this hard to use, and does this little. But if you need a secure line, Tails is the best way to get it. In the era of the NSA, that’s a rare thing.