I suspect their goal is to train a model for detecting adult material, so that they can block it, which isn't necessarily an amoral goal
e.g. if someone is reciting a poem they wrote in a public park, and I make a recording of that recitation, I have not violated their copyright in doing so, however I might violate their copyright by reconstructing that poem and then distributing it
And likewise if you distribute any sort of copy of the recording you made you are violating at least one if not more copyrights.
> however I might violate their copyright by reconstructing that poem and then distributing it
My argument is that the recording itself is not a copyright violation, not that distributing such a recording couldn't be construed as one (however I disagree on principle with that being illegal as well, as it puts an undue burden on the exercise of free speech, which should include the ability to accurately and entirely recite what I had experienced in a public place).