TL;DR because this turned into a lot of looking back on my relationship with my parents:
I’d make sure they knew I had the capability, and then, if I saw a need to use it, I would. I wouldn’t give an expectation of privacy and then violate it.
First, let me state that I’m in my late 20s, and have no children.
Secretly? No. Or rather, I would never hide that I have the capability, though I wouldn’t necessarily tell them when I was using it. If I had reason to suspect them hiding things from me, I might even hide the mechanism, but I’d let them know that I could check. The goal would be to indicate that whatever it is I’m concerned about is REALLY IMPORTANT (i.e. more important than privacy), and that I expect that to act as a deterrence.
On the other hand, I can’t think of many scenarios that would call for such action. I would make it clear, for example, that a diary is private unless I expect the kid to be in danger, but the scenarios that actually come to mind for when I would go through it all involve things like “E left without telling anybody where e’d be, can’t be reached by any way, and has been gone since yesterday” or similar; if it was a suspicion of something like drug abuse, my inclination is simply to talk about it, not even necessarily asking anything specifically. If you can show your kid(s) the utility of giving a positive weight to your views on a subject, then you can often avoid needing to do anything so drastic as violating their privacy (in any scenario where they reasonably expect to have it).
With all that said, I don’t really have a good view of how adversarial parent/child relationships function (or rather, dysfunction); I certainly didn’t always get along with my parents, and didn’t even always respect them very much (and oh damn but did my dad blow up when I told him that, circa age 12) but they never violated my trust on big things. It was never a case of me-vs.-him (most of my problems were with my father), but rather of my utility functions vs. his appreciation for my utility functions. He could make me incredibly angry by promising some treat and then simply failing to follow through (for what never seemed, to me, to be a valid reason to break your word) but that was because I valued a verbal promise of something trivial far more strongly than it warranted, not because he was inherently untrustworthy; to me, the breaking of a promise was a much greater betrayal than the loss of the treat. Once I learned to understand him better, I simply discounted any promise he according to how (un)important he thought it was (not how important I thought it was; I didn’t get so far back then as to think about “how important he thinks it is to me”). The only times he came close to breaking the big ones I could usually argue him around.
Took me a long while to work out the details there, though. Might be good to help the kid(s) in question understand where you’re coming from, and how much you value something like your implicit (or explicit) promise of their privacy. Of course, if you already have given an expectation of the child’s privacy being sacrosanct, I don’t know what I’d do in your place. If you’ve already been caught violating such expectations, my only recommendation would be to immediately explain why you fucked up because, if the kid’s worldview is anything like mine at that age (which it totally may not be, and I’m no psychologist) you sure as hell have. Not by the snooping itself, but by simultaneously creating a scenario where the kid had reason to believe emselves private and yet one where you felt it was justified to violate that.
TL;DR because this turned into a lot of looking back on my relationship with my parents: I’d make sure they knew I had the capability, and then, if I saw a need to use it, I would. I wouldn’t give an expectation of privacy and then violate it.
First, let me state that I’m in my late 20s, and have no children.
Secretly? No. Or rather, I would never hide that I have the capability, though I wouldn’t necessarily tell them when I was using it. If I had reason to suspect them hiding things from me, I might even hide the mechanism, but I’d let them know that I could check. The goal would be to indicate that whatever it is I’m concerned about is REALLY IMPORTANT (i.e. more important than privacy), and that I expect that to act as a deterrence.
On the other hand, I can’t think of many scenarios that would call for such action. I would make it clear, for example, that a diary is private unless I expect the kid to be in danger, but the scenarios that actually come to mind for when I would go through it all involve things like “E left without telling anybody where e’d be, can’t be reached by any way, and has been gone since yesterday” or similar; if it was a suspicion of something like drug abuse, my inclination is simply to talk about it, not even necessarily asking anything specifically. If you can show your kid(s) the utility of giving a positive weight to your views on a subject, then you can often avoid needing to do anything so drastic as violating their privacy (in any scenario where they reasonably expect to have it).
With all that said, I don’t really have a good view of how adversarial parent/child relationships function (or rather, dysfunction); I certainly didn’t always get along with my parents, and didn’t even always respect them very much (and oh damn but did my dad blow up when I told him that, circa age 12) but they never violated my trust on big things. It was never a case of me-vs.-him (most of my problems were with my father), but rather of my utility functions vs. his appreciation for my utility functions. He could make me incredibly angry by promising some treat and then simply failing to follow through (for what never seemed, to me, to be a valid reason to break your word) but that was because I valued a verbal promise of something trivial far more strongly than it warranted, not because he was inherently untrustworthy; to me, the breaking of a promise was a much greater betrayal than the loss of the treat. Once I learned to understand him better, I simply discounted any promise he according to how (un)important he thought it was (not how important I thought it was; I didn’t get so far back then as to think about “how important he thinks it is to me”). The only times he came close to breaking the big ones I could usually argue him around.
Took me a long while to work out the details there, though. Might be good to help the kid(s) in question understand where you’re coming from, and how much you value something like your implicit (or explicit) promise of their privacy. Of course, if you already have given an expectation of the child’s privacy being sacrosanct, I don’t know what I’d do in your place. If you’ve already been caught violating such expectations, my only recommendation would be to immediately explain why you fucked up because, if the kid’s worldview is anything like mine at that age (which it totally may not be, and I’m no psychologist) you sure as hell have. Not by the snooping itself, but by simultaneously creating a scenario where the kid had reason to believe emselves private and yet one where you felt it was justified to violate that.