Vitalik Buterin is taking to Twitter to defend Ethereum’s move to proof of stake. The Ethereum co-founder took a shot at Swan Bitcoin’s managing editor Nick Payton, who argued Thursday that any cryptocurrency that powers a proof of stake blockchain—which uses validators with pledged, or “staked,” assets to verify transactions—is a security. “The fact that you can vote on something to change its properties is proof that it’s a security,” Payton said. The insult hits at a sore spot for a crypto industry that has for years battled with the Securities and Exchange Commission—and one that is particularly touchy for ... (full story)