Otherwise anything might access the bus. Note: This will not work if the user moves to another html page. They will not have a port/key passed in the query string of the URL, so they won't be able to connect.
We are exposing it using a websocket server. The port of the server is passed in the search string of the file:// url.
An hello world activity using the script http://git.sugarlabs.org/hello-world/mainline/trees/html