I spent a long time thinking about how to prevent abuse and just spam, and unfortunately I don't think I have a good solution for it.

The idea though is that these domains are generated by people seeking feedback (or looking to talk about a certain topic) with a group of people that they at least have some sort of relationship with. It isn't really meant to be an anonymous message board where you set up the topic and literally anybody drops in and says anything they like. I was hoping that with an intimate smaller group where the domain is shared with only people the creator is interested in hearing from and trusts, this would reduce the amount of spam/abuse.