Myself, Masaru, Queequeg, and illaraza (other people probably deserve to be named) were the last active members of the nichiren sangha, which was founded by user MarkP, who had a stroke and was unable to continue to keep it up. Queequeg held it up for some time after, but in the end, it was too small, there were few active consistent members, it had run it's course.
There were others, but for myself I cannot talk about them as I did not belong to them, before my interest in nichiren Buddhism. We are just small is all. Though these things are also moving towards things like social media.