Always_Ask_Questions,
“Please show me halochos that say that being direct with people is always the right thing to do.”
Oooh a two-fer of argumentative fallacies in one sentence! This is both a straw man and shifting the burden of proof. Please show me where I said that being direct with people is “always the right thing to do”, and then show me halachos that say if your fellow is sinning, you should just watch and see how it goes for him.
“But let’s say the parent tried it 3 times already and the kid just evades it … [t]hen, yes, let them have their innocent fun and monitor for the signs that something bad is happening.”
Wow, at that point it is certainly not innocent fun, no matter what they’re actually doing online.
“Are you afraid that this violate R Gershom herem on reading letters? Then, just monitor IP addresses or inform the kid electronically as businesses do: “this device (network) is subject to monitoring”. “
Maybe, but on a more simple level, children deserve respect too. Even if you tell a child that their device is subject to monitoring, if they evade a clear rule and nothing happens for a good long while, they will assume they “got away with it” and their activities are not actively monitored. And if they find out 6 months later that you’ve been reading their chats, searches, etc. and never told them, that could humiliate them.