Facebook get its share amount of bad PR (some are well deserved), but we shouldn’t dismiss amazing engineering work because of those. This is a technical piece that highlights solutions to problems not many out there get to solve.
But they, like Facebook, deserve every bit of bad PR they get for being truly awful corporations.
I'm not saying the parent comment is absolutely essential, but I'd rather see that instead of people using this to change the conversation from central flaws in Facebook's data practices, business model, and ethics in general. This may sound a bit harsh, but at a certain point you have to really consider what giving publicity to a group gives them versus the inherent value of the paper.