It's an interesting question as to whether parents should check on the online activity of their children. It's difficult to imagine how one would arrive at the decision not to. With regard to how it affects their relationship with privacy, I would ask, if they ever gave their kid the car keys, if they ever checked the odometer in the car when it got back. Have they ever purchased a phone for their child and not checked the bill? Have they ever bought groceries and never checked what was in the refrigerator? I'm uncertain as to how that would be different. Checking up on what the child is doing, what they are interested in, what their behavior is in the real world, as opposed to a virtual world. A very large portion of a child's life now exists online. It's irrefutable and I think irreversible. To become alien to such a large portion of their lives is inexplicable to me.