Hacker attack shuts Bitcoin bank

Flexcoin, the Canada-based Bitcoin bank, is to close after losing $600,000 in a hacker attack. Its entire stock of Bitcoins stored on-line, in its so-called "hot wallet", were stolen. Coins held in "cold storage" or in servers not connected to the internet were not taken. Last week, the world's biggest Bitcoin exchange, MtGox, filed for bankruptcy protection after it suffered a $500m theft. Bitcoin is a digital or crypto-currency which is bought and sold online, but not backed by any country's central bank or government, according to BBC.