CowboyRobot writes: In November, Denmark-based Bitcoin Internet Payment System suffered a DDoS attack. Unfortunately for users of the company's free online wallets for storing bitcoins, the DDoS attack was merely a smokescreen for a digital heist that quickly drained numerous wallets, netting the attackers a reported 1,295 bitcoins — worth nearly $1 million — and leaving wallet users with little chance that they'd ever see their money again. Given the potential spoils from a successful online heist, related attacks are becoming more common. But not all bitcoin heists have been executed via hack attacks or malware. For example, a China-based bitcoin exchange called GBL launched in May. Almost 1,000 people used the service to deposit bitcoins worth about $4.1 million. But the exchange was revealed to be an elaborate scam after whoever launched the site shut it down on October 26 and absconded with the funds. The warnings are all the same: "Don't trust any online wallet.", "Find alternative storage solutions as soon as possible.", and "You don't have to keep your Bitcoins online with someone else. You can store your Bitcoins yourself, encrypted and offline."