I absolutely agree with most of this. Having open discussions is a wonderful first step and even more wonderful when it works. Telling them certain sites/privileges are off-limits and why, is also the most appropriate first move. Maybe even appropriate for moves two, three, and four, when they mess up and you give another chance, another chance and another chance (after progressively more severe consequences, of course). But then what if that fails? I think that probably most who find themselves on this forum have also found that the typical, reasonable methods don't work with these kids.
I have a tremendous problem with the concept of being so sneaky. I was raised to have a huge respect for personal privacy, and I would have been crushed if my parents had ever violated that for me. I never gave them reason, however, and that is the big difference. I believe that to spy, snoop, etc., without good reason is wrong, and it sounds to me like you have a similar value system. Just from an ethical standpoint, I think a parent should have some fairly strong evidence before resorting to such methods, but once there, I really think it's wrong not to use whatever means available to protect the family.
I strongly disagree that it is "too late" to audit "after the fact," though. That's where the "good reason" part comes in, when your difficult child lets you know your rules mean nothing. Even though it is at that point too late to avoid SOME damage, I've learned over and over that things can ALWAYS get worse.
