Do you post snippets of chapters or scenes from your manuscript or WIP (work-in-progress) to your blog or author website? If so, be careful! Please read what happened to Indie author Becca Mills. One of her published works was pulled from online platforms after a scammer used material from her blog to claim she took their work as her own.
The online reader/writer community is usually one of collaboration and friendship, but the world does have a few odious bottom feeders that think it’s funny to screw with people. The article is somewhat long, but if you’re an author I strongly encourage you to read through it.
Personally, I wish plague and pestilence on the vile douchebags that do this kind of thing, but in the meantime, protecting yourself and your work is the best way to go.