I couldn’t find the original article, but very similar articles cite this survey: https://mapresearch.org/brief/new-survey-reveals-dramatic-changes-for-lgbtq-adults-since-november-2024/ It seems like the article writers use the results from that survey together with population metrics to get the 400,000 number.

Another community that has sprung up recently is Reticulum. Some of the relay chats rooms, websites and forums on there feel like the early internet and the emphasis on direct communication over radios could prevent bots. But it’s definitely not ready as an internet replacement. Maybe in a few years…