2) One can generate random email addresses, and *verify* their existence. Hint: You can generate emails using (common names + a corporate domain), and check them against Facebook.”
Still, data is a tricky thing. It can be used in all kinds of unintended ways. That’s why you have to be careful who you share it with, and why companies like Facebook have a special responsibility to keep it safe and prevent bugs like this from happening. There are companies worse than Facebook at this, but there are also better ones.