How do you protect your community from the inevitable arrival of trolls who try to blend in and poison your photo collections with AI generated ones, only so they can say "see? it's so good, they don't even notice!"
The community has to be based on actually knowing people and a progressive level of trust. Just like other things in society: doctors and accreditations make sure that fake doctors don't practice, keeping sensitive information is based on trust, etc. An anti-AI community has to be a real community that is based on knowing and actually working with people, and not some online thing where anyone can sign up.
In other words, it's not a social network or an amusing website with a free account. Nor is it just about photo collections. It's about supporting real people who do not want to support or use AI.