岩戸鈴芽 said:
More seriously, a private favgroup you can share with select people could be useful, but I could see it being deemed outside of the scope of Danbooru.
It would lessen pointless pools (or good pools that haters perceive as such, quack). Also, how would collecting images under a theme/tags but with a little less scrutiny and specifically encouraging community involvement be off-topic here?
*After more thought while writing I can see why, but they would function almost the same as pools. One could argue that favgroups in general are pointless when you could just favorite your images and find them there.
Besides public and private favgroup settings a third could be added and called something like: Shared, Community, or Hosting favgroup.