Earlier quoted context omitted.
I mean, MtGox stands for "Magic The Gathering Online Exchange". They were literally set up to sell trading cards. The whole "being the biggest bank in a new $6bn+ economy" is a pivot. The whole system is crazy. But even by those standards, taking 35 grand and not noticing you didn't give them what they paid for stands out.
Aww, you guys are so cute. You think banks have this stuff under control? Auditors will "find" hundreds of millions of dollars of missing assets on the regs. Many banks are powered by duct tape and loose Excel spreadsheets. That's why things like Basel exist.
That's really not true. Yes, auditors do find missing assets like that, but some of these banks have trillions in assets. Moreover, these errors usually aren't things like cash in versus cash out. Accounting and tax rules are very complex. So an error might entail having incorrectly computed the value of certain tax assets or the like. More to the point, a major bank will have layers and layers of accounting controls intended to catch even very small errors. These processes are themselves audited every year, and stress tested. It's not duct tape and excel spreadsheets.