Within the USB is a full operating system (like Windows), and when you plug it into a PC, that computer will restart into your own personal set-up, called Tails, the Daily Mail reported.
When you have finished, shut down the computer, put the USB stick back in your pocket and the PC will never know it has been used.
Not a single trace is left on the PC, as everything the user does is contained within Tails, which means no cookies of websites browsed, no chance of documents being left in a Recycle Bin, the report said.
Though critics say this may allow people to carry out illegal activities in secrecy, privacy advocates laud the idea of being able to work in complete secrecy.
With Tails you can feel secure that no-one will be able to check your documents or follow your movements when your PC is either turned on in front of you, or squirrelled away in your pocket.
You just need to worry for one thing though. Not to lose the USB device.