this is silly, though. If the kids are in "adult" areas then they're still not going to see ads for lucky charms because lucky charms isn't marketed for adults.

and the several posts "an it harm none do what thou wilt" on this topic are silly too. My breath takes oxygen out of the atmosphere. Me drinking a glass of water takes that water out of the ground (or stream, or lake), making you unable to drink it. Every footstep changes the terrain.

It sounds good in text form "as long as they're not harming anyone but themselves" but what about smoking? assume someone lives alone so they're not second-handing anyone else, they're still a burden on the system. there's still poison being sprayed on tobacco crops, diesel being burned to harvest and transport, plastics being used to manufacture the cigarettes, and so on. There's external costs to literally everything except living in a log cabin made from local logs in the middle of a forest and only foraging and hunting for food. And even then i am sure i could argue that has unbalanced negative externalities.

If you're going to attempt to make a point, make sure it makes sense from more than one angle, first.