It's taboo in our culture to say this, but what keeps me up isn't just what people are afraid of; it's how far they’ll go to feel safe. That’s how monsters get made.
We’ll trade away the last scraps of online anonymity and build a legally required censorship machine, all for a promise of safety that's always just out of reach. And that machine sticks around long after anyone remembers why it was built, ready to be turned on whoever’s out of favor next, like a gun hanging above the door in Act One.
But say this out loud and suddenly you're the extremist, the one who "doesn’t care about kids." We’re already past the point where the "solution" is up for debate. Now you just argue over how it'll get done. If you actually question the wisdom of hanging surveillance over the doorway of the internet, you get boxed out, or even labeled dangerous.
It's always like this. The tools of control are always built with the best intentions, then quietly used for whatever comes next. History is clear, but polite society refuses to learn. Maybe the only real out-of-the-box thinking left is not buying the story in the first place.
Good example would be EU's proposed "chat control" regulation. Wiretapping every (even encrypted) channel for off chance illegal material might be shared.
If the token signifies you are 18+ and nothing else and if the generation limits are such as to be reasonable then people will generate some fraction of their total tokens just to sell them, or use their elderly relative's tokens.
The kids will be trading these tokens to each other in no time. Token marketplaces will emerge. The 18+ function of the token will just become a money/value carrier.
If you limit it to one token per person, the privacy implications will be devastating. All online presence where being 18+ is required will be linked.