• Repost spam and karma farmers.
• Also the bots that simulated activity by reposting the top posts with their highest upvoted comments from a year ago.
• Cross-site/server bans because you posted in a community that the moderators of the one you are trying to post in don't like. Sadly already happening with many servers defederating from each other.

It feels like at least 50%-60% of it are bots, same with Reddit.