Automated Trust Chain. According to their official statement, the accounts were reinstated following individual review. The vector is that legitimate accounts that don't break the ToS get dumped in a big set of accounts that actually do. A classic case of automated systems being gamed to trigger false positives. The vague statement about other accounts from the same set that couldn't be restored while not explicitly naming that these accounts were also phrack accounts makes the case even stronger. It was a denial-of-service and they blatantly didn't care until social media outrage hit them. I am not even blaming the CERT here maybe they were real false positives on their side. It's on Proton. They need to verify before taking actions against their own customers.