Stop Facebook from Spying on You...: And Other Ways to Protect Your Online Privacy (2015)
Best Privacy Defense When Using Wi-Fi
It’s important to make sure you are protected when using Wi-Fi.
How: Make sure that you have two-step verification enabled (for directions, search for “two-step verification” and the service you want to use, such as Google or Facebook). This means that signing into an account will require two forms of identity verification—usually a password you create and a code sent to you through a text message or with a special app. So, even if your user name and password are stolen, the thieves cannot get to your account because they will not receive the additional required code.
For the system to work properly, you need separate sign-ins and passwords for every online account and need to enable two-step authorization for all of them. Since this may significantly increase the number of passwords you have, consider using a password manager such as 1Password or LastPass.
Source: The New York Times