At a dinner last week, The Ledger observed Michael Casey and Paul Vigna, coauthors of The Age of Cryptocurrency and its blockchain sequel The Truth Machine, get into the sort of row that only coauthors (and perhaps long-married spouses) know. Casey downplayed Facebook’s seemingly omnipotent advantage in getting its cryptocurrency adopted and used, saying its incumbent position will not guarantee success. Vigna, smacking his hand on the table, pushed back, arguing that the the media giant’s reach--a...