In Facebook Groups it does nothing as of 2021:
Post in a public group.
Somebody comments on your post.
You right click and select "hide comment".
Now look at your post in your browser's incognito window
(not even logged in to Facebook.)
The comment is still visible to everybody.
I'm using uBlock Origin (which is anyhow very recommended addon) and used it to block these pop-ups. This is how:
Once a pop-up pops-up:
Click on the add-on's icon.
Click on the picker icon on the buttom of the window that opens:
Click on the pop-up you want to never show again (make sure you point the mouse pointer at a spot that selects all of the pop-up'...
Do you have a 'Page' which is an admin of the group? I've found that when I link my 'Page' to my 'Group', that functionality breaks in the group.
If I leave the group as the 'page' and just have human admins it starts working again.
Not really a fix, but a troubleshooting step/workaround. I have a ticket open with Facebook but I'm not particularly optimistic ...
Sir my sending Sms is block i don't know how to happen and know how send a rong sms to unknown propel i avoid to do this please this account sms very important For my femly so please unlock my sms on FB messenger thanks you Facebook team
Weirdly, after a while, FB simply stopped asking for approval from another computer. Never found a way to actually approve a login.
She remains totally locked out of her original account, but is seems to be able to use the repurposed bogus account.
It looks like Facebook changed the way we can hide the list of people that follow us. In my case, I was trying to do this in order to protect their privacy (as well as mine, since I'm not fond of strangers knowing who are the people that probably know me).
The way I found (as of July 2021) is to go into "Settings and privacy" > "Privacy ...