Visa (V) CEO Charlie Scharf suggests his company plans to join MasterCard in placing fresh transaction fees on PayPal (EBAY) and other online payment services deemed to be digital wallets. "I think it is totally appropriate to do that." Wedbush's Gil Luria isn't surprised. "This is a fully functioning duopoly. When one does something, the other one follows suit." Concerns about fresh fees from transaction processors have already pressured eBay shares.