I would tell. I, as well as many members of BGLOs , work too hard for our organizations. It's unfair to us that someone is out there misrepresenting themselves as members when they don't put in any work.
Besides, with the all the technlogical advancements we have in our society, it's not as easy to "perp" as it once was. So even you don't tell, it will come out sooner or later.