Let me put it this way: how would you go about measuring the harm that Facebook or any other social media company causes?
With cigarettes, oxycontin, or weapons manufacturers, you can look directly at the physical harm they cause. We have statistics and studies that require little effort to interpret.
With social media, it is nearly impossible to connect physical or psychological harm to a platform over the course of someone's life. The papers that draw conclusions in this space are based on limited studies and polls that could be influenced by any number of external factors. We judge these things based on little more than feeling.
Now, I think it would be great to be able to make informed decisions based on diligently collected data (and maybe that's what we should be fighting for) but we don't have that right now. Why, in this case, do we seem eager to throw scientific rigor and frankly due process out the window?