The highest profile one is /r/piracy. The illegal sharing part of the subreddit spawned a forum for good general piracy discussion. It was at serious risk of being deleted and had to go to extreme lengths to preserve the community that formed around the actual illegal sharing part.

https://www.vice.com/en_us/article/qvygwq/reddits-piracy-sub...

/r/datahoarders and /r/opendirectories are a couple other I personally have seen similar things happen. In my opinion they're a couple of the greatest subreddits out there so the fact that they could be banned out of nowhere on a technicality is a little concerning.

Interesting. Thanks for sharing. I suppose these are the results of the gap between technology and legislation.

There are similar adjacent problems with discord and violation of the terms of service.

Luckily most of these groups are tech savvy enough to run their own IRC servers.

I can give you another one. Reddit banned /r/Holodomor https://www.reddit.com/r/reclassified/comments/bedmbv/rholod...