Ask HN: Does an in-browser neural network have any practical use?

I am thinking of starting a small site which will allow users to train and predict locally within a browser. No downloads and training data will stay local and private (never sent to the server). Everything should happen using the local resources.

This web application should allow training data of type JSON or CSV. Perhaps it can also allow streaming from the local file system. I think we can support all types of Feed Forward and Recurrent Neural Networks with this application.

Technically it’s all possible but are there any practical uses for such a thing to exist?