yes, you're right. (Though I think it wasn't about a TV watching your food choices.) So what happens legally if, today, a company literally does it? How do you legislate against this?

It is literally possible for a television to include a punishment timer (as in, it is pretty trivial to code up, if the device isn't rooted.) What happens if a company sells one that literally identifies shopping and uses a punishment timer for people who buy a competitor to their sponsor instead of their sponsor? can you make it illegal?