Security is hard. Look at the email from Charles Delevan. It legitimized the phishing attack on John Podesta, and caused the compromise of Mr. Podesta's emails. All the advice in that email is good, solid, and accurate. But he claims to have typoed one word, where he typed legitimate instead of illegitimate, and the hackers were in. A good reminder that in security, you have to be right every time, and the attackers only need you to slip up once.