TOKYO -- Banks and other traditional financial institutions are grappling with the rise of virtual currencies that challenge core assumptions about the sector and could bring about a seismic shift in how business is done.
Near the Acropolis of Athens, Vassilis Papadopulos, a merchant punched buttons on an ATM with a large "B" on its screen. Instead of accessing money from bank accounts, this machine lets users buy and sell bitcoins for cash. After living through multiple financial crises, he has concluded that neither the Greek government nor the European Central Bank can be trusted. "Bitcoin is crucial to protecting my assets," he said. About 20% of his financial assets are now in bitcoins.