While I see where you're coming from, I don't really see how this could be addressed without very fat NDAs and a serious risk of leaking personal data. For comp

While I see where you're coming from, I don't really see how this could be addressed without very fat NDAs and a serious risk of leaking personal data. For comparison, you wouldn't expect say Apple to give researches access to their proprietary intellectual property. I very much agree with you that it could be very beneficial, I struggle to construct an argument for why Facebook should do this.