You will have to look in the app store for filtering software. As long as the isers do not know the SU password, if you set one, they cannot make changes. Suggest getting some books on Mac OS-X administration, along with looking in the Apple support forums, regarding this subject.
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"Ren: Now listen, Cadet. I've got a job for you. See this button? Don't touch it! It's the History Eraser button, you fool!
Stimpy: So what'll happen?
Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?"
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Posted from Apple iPhone