yes, hashchaining is useful

"BitCoin is copacetic if you want to collect ransom payments from people whose files you have surreptitiously encrypted. "

Setting aside the vocab lesson, people who would even consider paying ransom to hackerZ instead of going to their adequate backups deserve extremely little sympathy. Yes, I know it makes for successful sensational clickbait mainstream journalism, but this is LWN. We understand hard disk failure rates and off-site backups around here.