Most people are not aware that your Facebook messenger and all of your conversations with your friends and family and possibly even your work are not being encrypted to prevent you for being spied on. There are ways to turn on encryption settings but you have to start your conversations over in a new secretive mode. That being said the fact that by default encryption/your privacy is not being protected is greatly disturbing. If you care anything about your privacy you should really stop using Facebook messenger. You should also never share confidential information in Facebook messenger such as credit cards, addresses, and so on.