Well, since all files are encrypted on the client side, I can’t actually read or access the contents of the files being uploaded. That means I can't know what’s being shared. However, I’ll be adding clear policies that will allow me to delete any files that appear to be used unethically or in violation of the guidelines.

Since you have access to raw data as it is being encrypted, you can know what material is being uploaded. You could in theory maybe claim that data is encrypted on the client but it is your client served from your domain.