That's it Tails Project live OS released Tails 5.3, a live operating system which runs from every computer without leaving traces on the machine nor on the medianetwork.
This particular operating Tails was used by her former employee NSAEdward Snowden to stay hidden on the internet.
To use Tails, shut down your computer, and boot the anonymous OS from a USB stick instead of starting with Windows, macOS, or Linux. This is how you turn your computer into a very secure machine. You'll be safe even if you're using someone else's computer.