From the sound of them, some validation check was omitted and so bad transactions were allowed. Just like any other popular piece of open source software there are incentives for finding exploits, but there are a lot of benevolent hackers examining the code to uncover and fix them. That’s all there is website visit their website to multiple-input-multiple-output transactions! They’re a pretty simple variation on single-input-single-output-transactions. As in the single-input-single-output case this is set to 0, which means the transaction is finalized immediately. Line 1 contains the hash of the remainder of the transaction.