Following up on his tweet last night, Elon Musk this morning posts a chart of bitcoin (BTC-USD) mining energy usage, calling the trend over the past few months "insane."This latest tweet has cut short a decent bounce for bitcoin into the low $50K range. The price has now returned to $48.5K, down 14% from a day ago. The action in alternative cryptos is as bad or worse. Ether (ETH-USD) down 15%, Binance Coin (BNB-USD) down 14%, Dogecoin (DOGE-USD) down 24%.Bitcoiners are pointing out the fallacy in Musk's tweeting, noting mining has nothing to do with bitcoin transactions (which Musk's Tesla will no longer accept), and everything to do with securing the network (Musk announced his intention to hold onto Tesla's $1.5B stash).Crypto-related stocks are all down double-digit percentages this morning: Riot Blockchain (RIOT), Marathon Patent (MARA), Microstrategy (MSTR).Previously: Bitcoin plunges, crypto world erupts as Elon Musk questions energy usage (May 12)