Facebook uses a security measure called Login Approvals that sends a verification code to your mobile phone each time you use a different computer or device to access your Facebook account.

Two-step authentication sounds technical and onerous, but setting it up is simple, and it makes it way more difficult for hackers to access your most important email and social-media accounts.

Sign into an app using your phone number, and Facebook will cross-check it with the one on your Facebook account.