It's a bit paradoxical. There are way less things a kid can say that can get him in trouble than an adult. Even the most oppressive regime will not hold what a 4yo toddler says against him. The need for privacy should rather be less for a kid than for an adult.
What it means is that violations of privacy are creepy, period. We try to rationalise it by arguing that we get something out of it, but when dealing with our kids, we stop believing our own bullshit and it is just becomes purely creepy...