Facebook has activated end to end encryption for 900 million users of Messenger. Now, this will not let anyone monitor the conversation between people. However, this feature will not be activated till the users do not activate the Secret Conversation feature of Messenger. Also for activating this feature both parties have to install the recent version of Messenger.

However, this feature will not work in group chat. Encrypted chat does not support GIF and video support but you can use Photos and Stickers.

In order to activate this feature, start a new chat and tap secret or before selecting destination number toggle a button on the left top side.

For ongoing chat, users can tap 1 on screen to activate Secret Conversation.