The recent Facebook hack means that we probably shouldn’t rely on single sign-on services like Facebook and Google anymore.
If they had taken more care with their implementation of Facebook’s Single Sign-On feature—which lets you use your Facebook account to access other sites and services, rather than creating a unique password for every site—the impact could have largely been limited to Facebook. Instead, hackers could potentially have accessed everything from people’s private messages on Tinder to their passport information on Expedia, all without leaving a trace.
Check It Out: The Facebook Hack Betrays Trust in Single Sign On Services