Facebook is a for profit organization. This is the rule with organizations like this. If given enough time, size, and lack of shielding, any corporation will eventually cause harm in some way.
We seem to have less focus on "Nike whistleblowers" or similar, you get the idea.
But, on a larger level, I see several comments that seem to be implying that talking about the wrongdoing of one company isn't valid unless we talk about the wrongdoing of all companies at the same time.
I think that argument is faulty. If the argument were good, then it wouldn't be possible to talk about any company's wrongdoing because you'll always be leaving others out of the conversation.
Companies are case studies of a problem, any single one is insufficient information for coming up with solutions.
I don't want to defend Nike, but still, the fact that people are poor enough to send their kids off to factories to make shoes isn't Nike's fault.
But again, very different issue. Worthwhile to think about, but I don't think it should detract from this one.
If Nike makes a material claim to investors (e.g. that children labor is not used), but the claim is revealed to be knowingly false, then that's securities fraud.