My take on this topic,
It's an endless battle, best not to get started. As you can see, everyone has a fraud nearby. They are everywhere.
Unless the one in your area is directly affecting you, or your lineage or something, I'd let it go.
I even have one in my city who claims to be a disciple of my master, looked me in the eye and said it. I've let it go for now. Haven't discussed it yet with the master.