Got a reply from the person behind @mastodonanalysis
"Thank you for your note and I apologize for causing harm. As part of a class project I was trying to explore the topological structure of mastodon and identify structures for creating safe spaces in other online communities. I chose this name to alert admins to my intentions. I thought that the only harm caused by downloading data could be server overload which is prevented by API limits. The last thing I wanted to do is cause harm to your community and I have stopped downloading data."
@dashie That would prevent him. He already stopped.
That would not prevent any kind of real, privacy sucking, bot. Doing a stealth one is a breeze on the fediverse.