I've been learning in my law course about how laws are built from precedent and often need to be based on real things that have happened, rather than in anticipation of something bad maybe happening in the future.

So when it comes to facebook and other big tech companies, I feel like they should be regulated similar to how toy companies can't advertise violence to children, and tobacco companies can't advertise to children at all. Those laws are incredibly strict and written with the understanding that kids are vulnerable and naive, and can't really think for themselves. But that vulnerability still has to be demonstrated, and tangible harm has to be shown before a robust law can be written (meaning, one that won't be struck down as unconstitutional or unreasonable or whatever), and such laws are still in the process of being written for the tech companies.

So you could argue that they should back off of marketing to kids as a moral thing, but equally you could argue that they need to stake out their territory before laws are written that block off entire lines of business. The tech companies are behaving rationally, but the results can be awful. Society needs to fight back and protect ourselves with strong laws.