For one thing, the client has to authenticate itself to a HTTP daemon and be authorized by the daemon and the Metcast taker. Usernames and other client identification used in this authorization process have nothing to do with login names on the target computer. Furthermore, the location where the content will be stored is entirely under control of the taker. The uploading client has no idea where the data will end up at. As an example, I created a special virtual channel to push feed for Metcast decoders.
Publishing is done with the familiar w-shove .
It has to be stressed that this transparency does not compromise security. For one thing, a publisher must have proper authentication and authorization to submit data. There is no need to set up holes in firewalls. Upload directory names are not exposed. See the feed vtaker's source code for more details.