The only folks who can really do much to stop this would be the Lindens as I am sure they have access to IP address' etc.
However, I am sure this person is clever enough to use a proxy, should their IP be banned, it's easy enough to fake another.
All we can do as a team is to just keep ejecting and banning for now and hopefully the Lindens can maybe catch this person thru machine id or similar means and make it stop once and for all.
As for club owners sending out notices to VIP's telling them to ignore this on a daily basis, I don't agree! It's basically gonna stop patrons coming to the club if they see a notice saying "oh btw we are invaded by spam bots, ignore them thx". To me, that will deter VIP's from wanting to visit a club/area.
I am sure most folks (except noobs) are aware of the scam and know how to simply close their IM and ignore it....for now.