Yeah, not on Three's side here. It's not like ads are illegal / immoral / ianything. If a user wants to block, cool - not the ISP. Doesn't a portion of the online world depend* on ad revenue to exist? WTF are they doing?
Can anyone tell whether with this the Chromecast still needs to have an internet connection to work? In applications like digital signage would just want the Chromecast on a LAN - not with internet access.
I've had to roll my own stuff because of that limitation, which runs on a Raspberry PI plugged into the display. Would much rather have preferred to have a single Raspberry PI serving the content, and multiple chromecasts plugged into displays.