You demonstrate you have no understanding of what the word 'feasable' means.
OK, but we actually did this as a commercial service on analogue TV and we deliver non picture data on digital TV (satellite and terrestrial) today, it's just not USENET data.
One _cannot_ do this with 'modern' digital TV trasmission, because the _end-to-end_ technolgy does not support it.
Apologies for disagreeing, but this is exactly what the modern technology does. Digital TV (ATSC in your case, DVB-T & DVB-S in our case) has a multiplex of a number of independent data streams that can be data, video or audio. That is carried end to end. We do this now with other data - http://en.wikipedia.org/wiki/BBC_Red_Button It'd be trivial for us to display USENET directly to read on your TV or deliver it to the STB ethernet port
OTOH, if the signal originates as a digital stream, while it may be "possible" to multiplex in an additional data stream, said data stream will *NOT* survive _intermediate_ transcoding to an analog video stream before transmission to the end-user.
Indeed but that is not a digital TV system.
And, even if the actual digital stream is delivered to the end-user, a *STANDARD* digital TV receiver has no means to deliver that 'additional' information to the end-user in any usableform.
Standard DTV PVR with an ethernet port are a few hundred dollars. For the people who would actually receive this the box cost is trivial they just some software. If you have a USB or PCI DTV rx it is trivial to do whatever you like with the data. brandon