Facebook Embraces HSTS Preloading, Upgrading Links to HTTPS to Boost Security

Facebook announced on March 5, that it is turning on a new capability that will automatically direct users to an HTTPS secured version of a link target, if one is available.

The feature known as  HTTP Strict Transport Security (HSTS) preloading is being rolled out across facebook.com and Instagram. With HSTS preloading, a site link that a user posted as just HTTP will automatically be directed to an HTTPS link for a given site.