Spying on your kids is taking away privacy, however, with reason then they could spy.
I let my dad see some posts that I thought we interesting here, and he likes the board, says it is run well and to the point.
Now under suspicion of a kid drinking or smoking, I'd search if I was a parent.
I'm basically the middle child so I get some attention, not a load of it.
But its nice when your the quiet one who goes does his work and has fun on his own.