As cofounder of La Quadrature du Net (a NGO fighting for freedoms in the digital age, still waiting for your support ;) ), founder of Octopuce (my company) and more generally as an hacktivist, I often use Tails, a Linux distribution trying to enhance the anonymity of our communications and enhancing our personal digital safety.
Tails is very useful, not only because it allows me to carry important elements of my digital life in a simple USB dongle, protected by a strong password, but it also allows me to use the anonymisation network Tor in excellent conditions.
Sadly, I was missing an important feature, for me but also for all the hacktivists and journalists whose awareness I try to raise on digital freedom and personal data protection. It's currently not possible to lock a running Tails and require a password to unlock it.
After an hour of research, I finally found a simple solution, allowing you to lock your running Tails with a password, so that you can go away from your computer for a few minutes without putting your personal data in danger.