Maisie Williams asks about Bitcoin. Memefest ensues, and Elon Musk joins the party.

Maisie Williams – also known as Arya Stark, daughter of Lady Catelyn and Lord Eddard, acolyte of the Faceless Men, you know the one – is considering buying some bitcoins. 

On Monday, she asked her Twitter followers whether she should "go long on bitcoin" (going long, in traders' lingo, means betting that bitcoin's value...