Who decides what is "reasonable"? One's person or group's "reasonable" is another's call to regulation, if not censorship by various means.
How can this conundrum be solved on an international network composed of both adults and children accessing the same content?
I'm not expecting you or anyone else to chime in with a solution; I obviously don't have one myself. But ultimately, this information hydra we've created will need taming in some manner, or it may eat the world alive.
Here in the US, back in the fabled wild west, the solution was not to expect the law to be upheld by grocers, blacksmiths, or bankers. The public hired professionals. So, I reckon, maybe we need some laws to enforce.