It's a fun piece of trivia one crypto currency guy told me and it seems to be true.
The MtGox pivot from trading cards to Bitcoin was pretty dramatic.
So either McCaleb built a brand new exchange from the ground up in one week, or he reused code from his Magic card trading service.
McCaleb sold the site to Karpeles 8 months later, and 3 months after that, it was breached for the first time. Allegedly, the hacker used McCaleb's old admin credentials to arbitrarily assign himself any amount of bitcoin, which he then started selling off to crash the price. Since the price crashed to $0.01, the dollar value of the withdrawal limit represented several thousand bitcoin, which the attacker promptly sent off-site.
No matter if the site was reused code from a Magic card exchange, or was written from the ground up, it never should have been within a thousand miles of anything of value.
Or he spent some time writing the new service while the previous one was still running.
ಠ_ಠ
https://web.archive.org/web/20100701145902/http://blog.magic...