> Is that a threat? Who is "we"?

Nope, just an expectation that sweeping claims get backed up either by reasoning (like you just did) or a source

As for your reasoning vs your claim: you had made it seem like there was some well-known flaw or tool within FB to disable/intercept E2E. Or that we should expect an E2E-disabler functionality already exists.

I'm no FB developer, but I doubt it's as simple as one or two rogue developers adding in an "intercept mark's messages" functionality.

> That is always true when all the code in use is controlled by a single closed organization.

Fair enough, but FB/whatsapp messengers are probably some of the most scrutinized by third parties, as well as developers who would sooner or later blow the whistle (would hope so anyway). I would not take "mark is on signal so his messengers suck" to be a reasonable conclusion - and I'm not even FB's biggest fan.

Do you imagine it is even possible that FB has not yet been served a National Security letter demanding backdoor access, on demand, to any WA account of the spooks' choice? Or that there would be any technical difficulty in complying with such an order?