Yep sorry. Mod parent tired.
Thanks for the comments. I hope I can clarify some of the things people said here.
Re popularity of OTA vs. cable: Cable is more popular in the US, but that's just the US. Digital Terrestrial is much more common in other places - for example it's the most popular delivery method in Europe by far (page 39)
To whomever suggested attacks via the remote control's IR port: that sounds a lot of fun to try, but the IR receiver's much less sensitive than the RF jack, it has a much lower data rate, and it needs line of sight.
About the power calculations: 1 Watt (0 dBm) can cover an area of 1.4 square Kilometers, under reasonable assumptions. The math is in the paper.
One last thing: A big shout-out to Martin Herfurt, whose work on HbbTV security was our starting point.
The number of computer scientists in a room is inversely proportional to the number of bugs in their code.