Discovered this morning that Maven https://heymaven.com (a social media startup who's CEO is ex OpenAI "Ken Stanley: leading the Open-Endedness Team at OpenAI") is mass importing public posts from the #fediverse with no links back to the original and no way to delete them. It seems there is no Opt-out or Opt-in mechanism at all. It also has posts from #Bluesky pulled in via @bsky.brid.gy that are also not linked back to the original.
Here's an example: https://app.heymaven.com/profile/66927
Thanks to @emsquared for posting about it under the #ActivityPub hashtag which is how I discovered it...