Yep. No one is stopping them from having personal black list and refuse to work personally but they were claiming to ruin people's career inside and outside of Google and they were proud of it which is scary. Also someone was proposing public blacklist...
That's a huge one. I can easily see anyone who operates an internal "blacklist" of other employees as creating a hostile work environment. And from my understanding, those who did posted as such under their real names, so there's no investigation needed to track down who is doing it.
If there's an employee conduct we should all be able to agree is hostile, blacklisting coworkers would be it.
If I had been passed over for promotion or denied an internal transfer I was well qualified for, especially if I had gotten good performance reviews, I'd certainly be looking to have a judge subpoena those lists. That those managers felt so bold as to brag about it indicates that most of them are at it, or that they have tacit support from HR. And if I wasn't on one of the lists revealed, then we'd have to keep digging, or suspect someone had destroyed the evidence.
