Interestingly, such misrepresentation and abuse of the signature should be somehow punished? If not a ban, then disabling the signature, for life.
The best idea to prevent it influencing and deceiving many newbie is to ban signature forever. Obviously banning signature isn't a bad idea since the user is abusing his signature space for scam attempted, apparently trying to trick the unwary user. I support the flag too, and he really needs to be stopped.