If you are one of the billion people that uses messaging service WhatsApp, you should take the time to enable "two-factor authentication".

This new security feature has been rolled out to users around the world and only takes a short second to do. 

WhatsApp > Settings > Account

Tap on the two-factor authentication

This will prompt you to insert a six-digit passcode and an email as back-up. While inserting an email address is optional, you should do this as it will help you, should you forget your passcode.