Spimmers

It seems that the three cellular in Japan share blacklists of spimmers (BoingBoing). The word is new to me. It is supposed to designate Unsolicited Commercial Instant Messages (or are those SMS’s?). The author of the article questions the legality of such a blacklist, but isn’t the same thing happening with email. It would however be better if it were handed over to a separate not-for-profit company with public guiding rules.