Facebook today announced enhanced privacy and security features for Messenger on iOS, including a new "App Lock" feature. With this enabled, Facebook Messenger will require Face ID or Touch ID authentication before it is opened.
The company hopes that this will let users feel more comfortable when letting someone else borrow their phone, preventing anyone else from viewing private Messenger chats. Facebook said that the user's fingerprint or face data is "not transmitted to or stored by Facebook."
To enable App Lock, Messenger users can head to the new "Privacy" section in settings. In addition to App Lock, the company is planning to launch more privacy controls over the coming months.