A reader has a question about a Facebook message:
“I keep getting on messenger (from my brother) “This post is hidden because IF YOU WORK(ED) on …is a private group. Join if you work(ed) on the railroad (railfans welcome) to see posts from this group. Join Group” I asked my brother if he send it and he said no. I got the post two times within 20 minutes. I do not know if this is spam or not.”
Your message probably looked like this message my husband sent to me a while back.

My guess is that your brother probably wanted to share a post with you and didn’t realize where he was sharing it from. My husband didn’t realize he belonged to a private group of Gamera fans and that I wouldn’t be able to see the post. When a group is private, you can’t share posts with people outside the group. Your brother may not even realize he did it.
Now, the other option is that someone cloned your brother’s account and is sending sneaky posts attempting to get you to join the group. However, if it’s appearing in the same thread where there are other messages from your brother, it’s probably just an accident.