In a recent cyber attack, an attacker has taken an estimated $60 million in Ethereum's digital money (Ether) by exploiting vulnerabilities in the Decentralized Autonomous Organization, an investment collective. Ethereum is offering the new way of digital contracts called 'smart contracts' based on a distributed ledger system (blockchain). The raider took advantage of a "recursive call" flaw in the DAO's code-based smart contracts.  More info