Podcasts are just MP3s. Podcast players are just MP3 players, not platforms to execute arbitrary code from publishers. Publishers can see which IP addresses are downloading the MP3s, which can give them a rough idea of audience size, their approximate locations, and which apps they use. That’s about it. They can’t know exactly who you are, whether you searched for a new refrigerator yesterday, whether you listened to the ads in their podcasts, or even whether you listened to it at all after downloading it. Big publishers think this is barbaric. I think it’s beautiful. Marco Arment makes sense. Not that anyone’ll listen, I fear.