In June 2011, when customers of now-bankrupt bitcoin exchange Mt. Gox agitated for proof that the Tokyo-based firm was still solvent after a hacking attack, CEO Mark Karpeles turned to the comedy science fiction novel "The Hitchhikers Guide to the Galaxy".

During an online chat, Karpeles moved the equivalent of $170 million in bitcoin at today's market rates — the virtual equivalent of a bank manager flashing a wad of cash in a wallet to establish credit. The gesture — with a sly wink to the "geek" culture Karpeles believed he shared with many of his 50,000 customers at the time, including an interest in coding, manga and science fiction — succeeded.

By moving 424,242 bitcoins, Karpeles, then 26, evoked the random number 42, described as the "meaning of life" in Douglas Adams' sci-fi novel. "Don't come after me claiming we have no coins," Karpeles said, according to a transcript of that online discussion. "42 is the answer."