In Macleod's book, the Execution Channel is a TV channel that shows judicial executions in real time. The idea is that the Chinese write most of the software in the world, including surveillance cameras for prisons. They include code that sends a copy of what's recorded back to a TV station that broadcasts it. Nobody knows for sure who's behind it (except of course the Chinese). To bring it back to my idée fixe, this highlights the security risk of proprietary, as opposed to Open Source, software.
All Macleod's books are enjoyable, but are too complicated for me to follow. I could probably understand them if I maintained a diagram of the characters, plot and time-scale, but that would be ridiculous. In a few years, when our minds have been uploaded to computers that are orders of magnitude superior to our brains, I'll re-read his books, just to see what it's like to totally understand everything.
There is a certain 'alternate history' dimension to the book. Historical events that occurred in our time-line happened differently in the book. This is a subtlety that not so much pulls the rug from under your feet, but is like walking on a rug that has been put on a very shiny floor. It's also a brilliant way for the writer to never get her facts wrong. For example, Macleod calls Burkhard Heim, Gerhard Heim. Is that a genuine mistake, or is it a subtle deviation from our history?