Should schools not allow parents to check their child's grades without their permission ?

I don't agree with the statement because this may pose an adverse effect on students' academic performance. If parents know each grade of their own children when the grades are good, parents can encourage children, and when the grades are not good, parents can communicate with their kids or even hire tutors to help them to improve their study, which is beneficial to their kids. However, if having such a rule, sometimes students may conceal their grades, especially bad grades, then their weakness can't be fully exposed and fixed, which may lead to more serious results. Thus, I think parents should have the chance to know children's grades without any limitation.