I was looking through the website and I noticed that a lot of the older images are Gone what happened to them? and if they still exist where can I find them?

Give some examples?

From this thread: hypnohub.net/index.php?page=forum&s=view&id=105951 Slayerduck said "35% of samples/thumbnails failed to generate. any broken image needs to be deleted as original image may be corrupted."
I asked about this in another thread and he said the images that are corrupted can't be reposted, as once they're deleted, they're on a blacklist of sorts.

I'm guessing that that's because the md5 is blacklisted. If that's so, changing some metadata or changing a pixel value by an imperceptible amount should still be good.