Parents are allowed to spy on their own kids...
The first two AC comments ("Counselling" and "What!")are really stupid. These parents were being responsible for their own kid. Obviously, she was being brainwashed by the teacher, and it was the parents' job to protect their kid, even to the point of secretly monitoring her Internet access.
Graham Marsden, the parents most likely had already taken the steps in trying to establish/maintain trust with their daughter. Since she started lying about her activities, it was time to take it to the next step ... monitoring her activities. If someone consistently lies to you about something, is that trust still there? No.
Several items to consider:
1. Anyone under the age of 18 years old (at least in the US) is a juvenile, and his or her actions and inactions is the responsibility of his or her parents. (At least that's the theory ... too many parents make excuses for having out-of-control kids, but that's another blog)
2. The juvenile has no guarantee to privacy with his/her parents. Now, it would be very bad parenting to not provide an environment of trust where the juvenile should become a responsible family member, but that trust is earned, not given.
3. The juvenile is not mature enough to think for him/herself, and there are legal definitions supporting this statement. Why do you think teenage drivers have more accidents than older adults? Because they act like morons but they think they are smart.
4. If this relationship came to an end where the girl hitched up with the teacher, and she became pregnant (or worse, killed), is that better than the current situation where she was monitored by her parents? You tell me.
As far as I am concerned, I support these parents for taking responsibility as parents to monitor and manage their kids.