As a parent I very much understand the reason why you would handle it that way.
Here’s why I’m hesitant to go all the way like you do, though: Our behaviour changes when we know we’re being surveilled. By knowing that her parents can access her private chats and messages whenever they want, not only may the way she phrases certain things change but she may also grow up feeling that surveillance is a natural thing and may thus be willingly accept excessive surveillance and invasion into her privacy that is more and more done by companies and public authorities (even in so-called „free countries“) nowadays.
I’m not saying that we shouldn’t be vigilant about what our kids are doing online but I’m afraid we’re making things worse by exercising total control over them.
But we ARE being surveilled. Not necessarily always by the government, but by big business and advertisers. There should never be any assumption of privacy on the internet. That ship done sailed.
I found and replayed for the kids every one of the queries made to OK Google on my account, including all the questions they asked about exploding farts.

I showed them the extensive records Google keeps on me. Apple has a similar log but end users don’t have access to it.
Then there is the harsh reality that some of our texts are encrypted and “private” depending on the service used, but only until your “friend” on the other end decides it would be advantageous to share something you think you’re texting in confidence with the world at large on another social media forum.
There are some talks I give to the kids before entrusting them to sleepovers and cellphones and so forth. The talk that initially garners the most skepticism but always has them coming back to tell me “OMG, you were soooo right” is “The treachery of Friends.” For it is a simple fact of life that even the best of friends at certain ages and stages do certain kinds of crappy things to each other and it’s perfectly normal part of growth and development, but something to be aware of. It doesn’t mean that one’s friends are evil twerps, just human and that as humans they make mistakes that can have horrible repercussions they’re too young to foresee. And yes, even adults still do stuff like this. So...
We ALL should exercise careful thought and discretion to every word we commit to electronic form.
When my husband and I give access to a piece of technology or give the gift of a cellphone, we explain outright the access comes with terms and conditions set by us. They know they can circumvent the rules but mostly they do not, because there aren’t any rules in place that are to their detriment. We are happy to explain why we do what we do. They know we are their first, best advocates in this world.
Our rules are sensible and reasonable in that they are meant to address real problems a person could actually expect to encounter.
And no matter how much they may verbally protest, children and teens and even young adults seek boundaries and guidance. At least until they can gather enough experience and perspective to form their own boundaries. Without rules and limits and some structure, it’s actually very challenging to define oneself and find one’s center during the formative years.
Did you ever wonder about how easily it is for some young people to fall into cults or get drawn in by someone charismatic who tells them what to do? There can be many varied reasons, but to me it often seems like at least some of these people didn’t get that gradual handoff from parental policing to self policing. That’s something my husband and I strive hard to do, to let everyone know we are building only a foundation but they will eventually be taking the control and building the rest of their lives.
Reasonable, well thought out rules and boundaries don’t make kids more apt to be automatons. They’re actually necessary at certain stages of development for healthy psychological development. Once the developmental milestones are reached, you have an adult who actually can think for themselves and resist thought control from less scrupulous people.
But here’s one secret: I do create some rules I pulled out of my butt that have zero real world serious consequences if they are flouted or broken. Most pertain to standards of room cleanliness, some arbitrary dress code type of stuff, and language. Don’t get me wrong, the rules are still good ones, but nobody is going to end up trafficked or humiliated for life if they’re broken. The kids hear me complain about the state of their rooms, see me glare at poor grammar or attempts to create their own profanities, and tell them to go back to their rooms to change to an outfit better suiting the occasion and they feel like they’ve put in the requisite amount of rebellion when they address these issues on their own terms or get me to compromise. They’re happy, I’m happy, and the really important rules remain fully respected and intact.

And they are happy when they get to grouse with their friends about my “rules” —that really aren’t the rules they think they are. In fact I’ve overheard them exaggerating about how strict I am on those rules. I’ve asked about the exaggeration and was told “Ah, nobody wants to hear I’ve got a sane mom when their mom is a dragon.”
