On Sun, 13 Jan 2013 22:04:35 -0800 (PST), Truth Teller
wrote:

Does Sirius/XM Radio know which station each of its subscribers is
listening to? I'm not looking at this as a nefarious "big brother is
watching you" thing. Rather I'm wondering if they do so to measure the
ratings of their programming. Considering each subscriber's radio has
its own identification number it seems doing so would be relatively
easy and a smart business practice. Anyone know?

In a word, no. There is no uplink from the Sat Radio receiver to
anything. Doing so would require a transmitter, which would be
subject to a whole lot more FCC regulation and restrictions on use.

It is very analagous the VideoCipher used on Sat TV. It is strictly
one way. The received looks for authorization messages whenever it is
powered up, but has no way to acknowlege the message.