Facebook messenger being logged into by another person

[ArchangelMichael]

Yes how do I keep someone out of my Facebook messenger or find out who it is 

[meself]

Think they have option to block users

[patriciostarr]

Just block that person tap the on top right you should see an option to block that user. Good luck

[conqureign]

i would go to settings ,access your information,and check out log in information it will show you where your logged in,what devices have access and login logout info. you can remove access for unknown devices in the facebook app. but in messenger you could set up app lock or check out the encrypted chats where there are other options

[realaud · Accepted solution]

Secure your facebook accout and contact Facebook. This is a Samsung forum.

[The_Chief]

Exactly - change your Facebook password and keep it secure with multi factor authentication.