That would be extremly hurtful to the adult industy, and un-wise on Visa's part. The adult industry is alway the first, to come up with new technologies that drive the internet.
Sex does sell, we all no that otherwise we would not be doing what we all do! However at something in the 5-10 Billion dollars year rate of online tansactions just for porn, Visa would certainly be prettty stupid to let that kind of money go.
MHO,
-ASF
http://www.adultsexfactory.com