"... we immediately banned Kogan's app from our platform, and demanded that Kogan and Cambridge Analytica formally certify that they had deleted all improperly acquired data. They provided these certifications." How is it at all possible to certify that data has been deleted and no copies were taken..?
This feels strange to those of us from technical spheres, but much of the world works without formal verification of facts. There are in theory severe penalties, both implicit and explicit, that ostensibly act as deterrent to bad actors. This is usually only noteworthy when it fails, but by and large it works. The friction involved if we did not generally accept someone's (signed, notarized, appropriately formalized)…
This predisposition to believe our fellow humans is actually hard-coded into our genes. This is one of the reasons it's so easy to spread fake news. The ability to lie to someone without direct consequences to yourself (because, for example, you are thousands of miles away) was not part of our ancestral environment, but it is part of our contemporary one, and some of us are exploiting this newly created ecological niche.