Do schools still have libraries? They did when I went, and you can be sure they curated the set of books in the catalog and kept records of who checked out which ones.
Better to learn that lesson in school, when the mistakes that teach it to you will be confined to your juvenile records, than to learn it as an adult when it can follow you for the rest of your life.
If anything, more people reshare criticism more publicly than ever, even as they are being surveilled.
Admittedly, the difference is that our society thinks it's OK to punish kids and teenagers to make them get in line. That's the actual problem and the solution is not to have them hide their thoughts as much as to respect them more as human beings.
All it led to was a lifetime of learning how to improve my opsec and now I work in the field myself.
Continuous improvement!
What happens when they start participating in denocracy. It's hard to imagine they'll have the same expectations of personal privacy after that.