In the year 2016, and going forward, encryption is your friend. This point cannot be emphasized strongly enough, as there is a growing number of third parties who want to eavesdrop on your conversation. Not that you encrypt to avoid getting caught while doing or planning something unlawful, but because your right to privacy is not something you should take lightly.
What you should know about Facebook Messenger encryption
Unlike encryptions on other messaging apps, Facebook Messenger allows you just one encryption per device. That is to say, you can either encrypt chats on your smartphone, and not your tablet, or just your tablet and not your smartphone. It comes enabled by default on the first device to get the update. If you enable it on a second device, the first device encryption mode becomes automatically disabled. Lastly, it is not available on the web version of Messenger.
Even with the encryption mode turned on, it does not encrypt all your messages. You must decide which messages you want to be encrypted. It also comes with features such as the ability to set the time before a message …read more
Read more here:: How to encrypt Facebook Messenger chats and why you should do it now