So long as they were basically OE bits, you wouldn't really be any the wiser. One fork stanchion looks remarkably like another. Of course, if they tried to flog your Ben Bostrom rep fairing panels, well, I'd agree with you.
Membership...erm.... Who cares if someone is new or not? If its a clear spammy job, you now a post in every sub forum, just get it removed. If its selling something, who knows those against may actually find its that rare part they have been looking for and snap it up Live and let live