But discord servers aren't considered "public spaces", hence the concept of an "invite".
This is akin to someone revealing they've been going to private parties and secretly recording everything.
It might not be illegal, but it's definitely not polite.
It sounds more like they went to the mall, picked 10% of the stores, and recorded conversations taking place in those stores.
> In this regard, this paper introduces the most extensive Discord dataset available to date, comprising 2,052,206,308 messages from 4,735,057 unique users across 3,167 servers – approximately 10% of the servers listed in Discord’s Discovery tab, a feature designed to highlight public servers that users can join.