This "direct broadcast" is in addition to the arranged, higher-bandwidth, downlinks of science data that feed the near-real-time pipeline (mentioned above, a couple hours behind realtime) and the regular science data pipeline (archival science data, days behind realtime).
This has more clout than you notice at first. For starters, it illustrates that satellites are really up there. I know, only the insane are Flat Earthers any more, but still, it's hard to imagine "from orbit". This kind of thing puts "in orbit" into the hands of everyone.
We used to do this at school in the '80s using a BBC Micro and some hardware that you could purchase. It's good to see that it can still be done -- they haven't encrypted the downlinks.
Why would they? It would just be a lot of hassle and money for something that is released for free anyway. You can get the same images off of NOAA's web site.
I hope that the control link is authenticated and encrypted in someway.
I work in the scientific satellite industry, and as far as I know, nothing is encrypted (possibly not true for military satellites). Sounds crazy, but I think people are more worried about reliability than security. Pretty much an accident waiting to happen.
Edit: It's more of a security through obscurity setup. The command codes aren't published (plus, they're protected under ITAR), and probably vary quite a bit per satellite. I think they are just hoping nobody takes the time to figure out what bits to send.
http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/realtime.... http://lance.nasa.gov/imagery/rapid-response/
This is very useful when you want to zoom in on an interesting natural disaster (fires, flooding, hurricanes, dust storms).