What was once an optional security feature by Facebook for the users is now turned on by default starting this week that encrypts data between users and company servers. This feature uses TLS (Transport Security Layer) in which encrypts (scrambles) the data transfer thus providing greater privacy between the two parties in the transaction. When it was an option, more than 1/3 or Facebook users opted for the feature, but only now it is setup by default.
This action to use TLS took the assistance of 3rd party application developers upgrading their platforms to help with browser compatibility. However, there are still compatibility issues with certain mobile devices such as phones in which Facebook will use less secure connections with these known devices or carriers.
For more detailed information, check this article by Network World Website – Click Here