BitcoinSpinner is NOT an on-line Bitcoin Bank. Nobody can run away with your Bitcoins. It is implemented on top of the BCCAPI, which means that all the heavy lifting associated with managing the block chain is done by a server. The server side is in no position to spend your Bitcoins, as all private keys are stored on your device. More info on the BCCAPI. BitcoinSpinner comes in two versions. This is the one for real production Bitcoins. If you want to try it out with worthless test Bitcoins look for BitcoinSpinner Testnet.