Surprisingly good article.

We had parental controls on our daughters iPad but it basically never worked as intended. Either she couldn't access stuff which she needed at school or she figured out the password by asking mom to extend it and watching her puttin g the password in or the system clichéd and allowed websites and apps which were clearly in the blocked list.

Now that she is in middle school she has to use a Mac computer, there we removed the parental controls and I only block the websites she shouldn't use (it's a very short list) and I just use the /etc/hosts file to redirect to localhost. If she figures it out we will see her using rose sites on her computer but if she does I'll be very proud of her investigating and learning about computers. I'm afraid she can't figure it out without hints though.