There are all kinds of laws regarding on how parents should treat their children and one might argue that keeping non-age appropriate material away from them is a reasonable line to draw into. For example in here with movies it’s pretty common practice (depending on a theater) to allow kids to ‘higher age bracket’ PG-rating with a guardian.

But the whole problem, at least from my point of view, can’t be solved only by either technological or legal barriers or solutions. Parenting is a tough job and from what I can see there’s really not enough support for them to do the job. “It takes a village to raise a child” used to be pretty commonly understood approach where all individuals from school bus drivers and cashiers played their small part on educating kids on how to behave and how the world works. Today it’s just rules and regulations which adults can use to hide behind and avoid taking any kind of responsibility and also, at least on some cases, the same rules say that you’re not even allowed to intervene if kids are being kids and do something stupid.

Obviously a lot of things are better now too than even in the 80s and 90s when I was a stupid kid, but I’d say something is also lost on the way.