Ars Technica – (International) Hacker steals $250k in Bitcoins from online exchange Bitfloor. The future of the up-and-coming Bitcoin exchange Bitfloor was thrown into question September 4 when the company’s founder reported that someone compromised his servers and made off with about 24,000 Bitcoins, worth almost $250,000. The exchange no longer has enough cash to cover all of its deposits, and it suspended its operations while it considers its options. Bitfloor is not the first Bitcoin service brought low by hackers. In 2011, the most popular Bitcoin exchange, Mt.Gox, suspended operations for a week after an attacker compromised a user account and sold all of his Bitcoins in a firesale that temporarily pushed the price down to zero. The site survived the attack and remains the leading Bitcoin exchange today. Hackers made off with another $228,000 in Bitcoins from online services earlier this year. Bitcoin’s peer-to-peer design means that transactions are irreversible. Once a transaction appears in the blockchain, the global record of Bitcoin transactions, no one has the authority to reverse it. And the pseudonymous nature of Bitcoin makes it difficult to trace stolen Bitcoins to their new owners.