> But where are they hearing about these effects that get them so concerned?

From real life? I know parents of middle school and up kids and they have first hand experience of the effects of social media and I’ve heard very little that’s positive.

I’m not saying the media aren’t trying to influence people but again, Occam’s razor: I really don’t think these parents need Rupert Murdoch whispering in their ear to be concerned about social media and kids.