when i signed up for mobile service or for internet service in china (i don't remember the specifics), i was given half a dozen sim cards for use in my family. so they were all tied to my or my wife's name, but used by anyone who needed one. i believe the in-laws got at least one or two, and my kids would have gotten one, had they been old enough to have their own phone. i don't know if there was any rule that would restrict who we give those cards.

the actual users of each simcard did not have to identify themselves. so at least then it wasn't about age controls, but it obviously would allow tracing the owner eventually.