Read nothing scandalous about Facebook's behavior. This HN headline doesn't deliver. There is nothing wrong with the request to keep this quiet for a bit so you can investigate. This is not uncommon in the security world where vendors get some time to get their stuff together and release a fix. Depending on the severity of the issue and the risk of abuse.
“Oh and by the way, you are not allowed to disclose any part of this conversation; it is a secret that we are even having this conversation” If this is true, it's practically begging for the blogger to research the law, and publish the whole conversation because FB has no right whatsoever to make such demand. I wouldn't call it scandalous, but it would certainly be a pretty dumb thing to say. If I had to guess, I wou…
If that quote is genuine, it still reeks of a stupid statement of an individual working for Facebook than a deliberate policy of Facebook to silence such people who find security issues. It's such an obvious dumb request. Don't attribute to malice what can be attributed to incompetence. Facebook is not incompetent, but it's not infallible either.
I'm withholding judgement here. I'm not sure all info is available.