Because "somebody has to think of the children." At this point, I am convinced parental instincts are being abused to slowly but surely install more-or-less complete public surveilance. Its a rather obvious approach. You have to appeal to something emotional. And parents, and their apparent unwillingness to take up responsibility for their parenting, are the perfect target. Even child-less adults will chime in to toot the "Somebody has to think of the children" mantra.