Are you thinking of user-to-user sharing (ex: daniel shares his list with justin) or something more global?

To give an example: The indiehackers website uses firebase as its data store. It's a blog/forum, so posts and comments made by individual users can be seen by people who don't have accounts. Is this a use case you plan to support in the future?

If not, the potential use cases are much narrower than firebase. Not necessarily a bad thing but I'm just trying to understand the product.