Locking your computer may feel like enough to prevent someone hacking into it, but even password-protected PCs are vulnerable to being hacked by a simple £4 device that can steal login details to popular websites in less than a minute.

The PoisonTap, which is made of a £4 Raspberry Pi Zero microcomputer and a USB cable, emulates an internet connection to hijack all of a computer’s internet traffic, stealing the data used to log in to websites like Facebook and Gmail.

It works on computers that have been locked but have a web browser left running, as is the case with many PCs that are locked for a lunch break or meeting.