[nerdybook]

iOS: 8
iPhone: 5S

I can't seem to find "sign out" feature anywhere. I tried that help/privacy terms > click on three bars thingy but it is useless, it signs you out but still anyone can sign in, as you, easily (even if you have 4 digit passcode on your facebook app).

Thanks.

How to Logout of Messenger iPhone
Open the main Facebook app.
Hit the menu bar for MORE and select SETTINGS.
In the Settings tab select SECURITY.
Hit ACTIVE SESSIONS.
Find the entry that lists these: Device Type: Facebook Messenger on iOS 8. ...
And hit the X icon next to that log to end its session.
That's all. You're done.

Good tip

What's annoying me after finding a way to log off by clearing data and cache in app settings is that I open the app up and it has the tab to log in to my account. No need for to type in your password. You just click the box to log in. WTF!! I am a memory card away from deleting Facebook and filing a lawsuit for invasion of privacy and tormenting. Once my pics are saved from Facebook, I'm done with it.

I believe it is because you are still logged into the facebook app as well, since messenger and facebook are connected.

Your account information could also be saved under settings>passwords & accounts>Website & App passwords.

If you're worried about privacy, you should probably check off "off facebook activity" on your phone. If it is checked on Facebook basically tracks your activity on your phone when you use apps other than Facebook. It's kinda creepy. Facebook descries it as "Off-Facebook activity includes information that businesses and organizations share with us about your interactions with them, such as visiting their apps or websites".

For iPhone iOS 13.4.1
Facebook> settings & privacy> settings> off-facebook activity
Alternatively you can also search settings for "off-facebook activity"