I belong to a few handfuls of mailing list, message forum, and Facebook group dedicated to Genealogy. Every so often, someone discovers that a picture, story, or details from their ancestor has been copied and added to a stranger’s family tree and is very upset. Often, their reaction is to make their research private, so no one can see it.
It’s an understandable feeling; genealogy is a very personal effort. You’re spelunking into your own history. It’s natural to feel protective of it, but that instinct may deprive others of their history.