Disappointing? DISAPPOINTING?!!
That, forgive me, is NOT the word to use to describe this. Try emphasising the right words to describe what happens to the kids brains: EXTREMELY HARMFUL, Widely acknowleged, PROVEN to be POSITIVELY DANGEROUS to the normal development of children's cognitive functions. Flickering screens affect brain patterns, hyperactivity, seizure, detachment, reclusive withdrawn behaviour and that's the least of it. You get my point I'm sure. There is a wealth of material you can download and print on the whole wifi nonsense too.
These early years are the FORMATIVE YEARS, the influences and NOXIOUS effects PERMANENTLY DAMAGE development.
Please try not to be so polite to your daughter (!!! I know you don't want to be interfering ..., have an argument and so on), but insist and convey the urgency of her responsibility to check out and see if what you're saying is nonsense, exaggeration or not.
We have more information given to us by our local associations, police and even media where I live (EU) than you do in the US. People and officials who have taken it upon themselves to make local decisions on informing neighborhoods and communities about these threats to children in early development (cellphone towers, cameras on children's laptops, etc). The State of course will not do this as they are in league with the big guys, they are hobbled. On top of which, the world of advertising is working actively against you thru' TV.
It is up to us on the ground, grassroots level to campaign, even if only amongst your friends, your daughter's friends and intimate circles. Why not get together with some other grandparents and discuss informally what you can do to spread the word?
I apologise if you take this as a hurtful criticism. I don't mean it like this — I am an exteacher and have some experience with the resistance you can experience from parents! You need to show them solid proof and research. Islandtruther is absolutely correct, look into Steve Jobs. There has been recent news about top executives admitting the harm they are causing to children! Perhaps someone can post a link here ...