Our behaviour and the behaviour of the people in our lives is both the biggest threat and the best line of defence when it comes to cybersecurity. Together we are the Human Firewall, and this was the subject of my TEDx Talk on which this is based.This little book is designed to be an easy to access primer on the vast subject of cybersecurity, it's aimed at anyone who uses a phone, tablet or a computer who connects to Wi-Fi or has a social media account. It's based on the successful TEDx Talk on the subject which is a 16-minute key point rundown of hugely important a topic. The book is not intended to be exhaustive, but it is an easily accessible for everyone and it's a great eyeopener which incites important conversation both in the home and workplace.This is the second edition of the book and in it I have removed the references to some of the scams I described in the TEDx Talk, I've done this so as to make it suitable for an audience of any age.