> It's mind boggling to me that this wasn't done a year or two ago. Two years ago, obtaining the same amount of bitcoins as this attack did would net you 1/100

> It's mind boggling to me that this wasn't done a year or two ago. Two years ago, obtaining the same amount of bitcoins as this attack did would net you 1/100th the profit in dollars (bitcoins were around $6 a piece two years ago). I think it's likely that attackers started considering this scheme around a year ago, when the bitcoin price shot up to $100, and the potential rewards became sizable.