For people who are still confused about how a place can be publicly accessible, but you can still lure people there:
Say you like to steal people’s shoes. You can go around the city and steal shoes sometimes, but it’s kind of hard to do and you’re worried you might get caught. “I know,” you say, “I’ll build a park specifically designed to make it easy for me to steal people’s shoes!”
You create this park, drop invitations all over the city to invite people to your amazing park with cool slides and a basketball court, and you also invite all of your shoe stealing friends to the shoe stealing hub where you can plan the best way to steal shoes.
Sometimes, one of you will see someone outside of the park with a really cool pair of shoes. You really want those shoes, so you personally give them an invitation to this park and encourage them to come. Once they do, it’s really easy to steal their shoes.
The park is the “private” Discord server, which was easily accessible with an invite link that was left in multiple locations where Moony’s fans would be drawn in.
The hub is their truly private chat where they planned their attacks.
And the shoe stealing? That was their targeted attacks against creators they didn’t like, either out of jealousy or bigotry.
Even if they can’t get away with creating a full server to host their bullying ring again, though I think there’s a chance they could, the behavior will continue wherever they can find their fans.