I'm sorry to hear of your troubles. I guess things are different a bit with providers because our name, persona and taglines: is our brand. Much the same as yours. It's our reputation being f-ed with and it is costly to an SP (to a pooner, also). To our reputations that can come into question when you see similar names, handles, ads etc
It isn't a rarity nowadays. I've had to pursue the right to my persona,legally. I have numerous "oops, I didn't know I was copying you" incidents. I have to send said providers emails, contact admin and I would like to just happily be me without being plagiarized in some way several times a year. A total nuisance.
Moreover, your handles are being used several times without you knowing it, in order to gain access or to cheat on an SP's booking system. I never ask for a handle, unless it's in the email address and I happen to remember it, I would know. I would say that I know the handles of maybe 10% of everyone that has seen me.
SD