Ah yes, those are Facebook notices indeed. They would only appear for people following links from Facebook to your site, not for any other users.
This type of message being presented to their users is often the result of:
* someone having reported one of your posts as spam, offensive, or some other type of complaint on Facebook. Now, don't panic, this happens all the time, People are known to flag things they might simply disagree with as offensive. :)
* they match a word in your post title, description or URL that could be deemed suspicious by their own algorithms. In that case, I'm not certain since it's not on the WordPress.com end, but maybe "cult" triggered it.
I believe there might be a process on Facebook to have a link re-evaluated, and the message removed. I'll ask, but you might also find it in their documentation: https://www.facebook.com/help/