A lot of the images I'm looking into say they were posted just a few days ago.
The source link of the majority of recent nude_filter images had gotten removed. I have been watching them for several days and noticed the sources were being edited out one by one.
I checked the editing histories to see, but some of them have too many tag editors for me to actually know who removed the source. Since it only pinpoints tag changes, not source changes.
But any time a mod or user flags an image or makes any change to it, it is shown there, so I had hoped I could figure it out the next time the link is removed again after I add it.