I’m not totally convinced by the narrative that Mark doesn’t trust his own tools so he prefers Signal.
"I was curious to check it out.. it wasn't very good, so I reverted back to Messenger/Whatsapp."
IIRC, he made similar comments when he was spotted using G+.
Disclaimer: My views are my own (and not necessarily shared by my employers).
I will take this moment also to mention that "re-implement" isn't exactly right in that they modified the protocol slightly to allow for someone in control of the administration server to change a user's private key without their knowing, so that the admin can decrypt the E2E communications using the known key.
Do you have a source for that claim?
https://boelter.blog/2016/04/whats-app-retransmission-vulner...
The GP claim is far broader that all E2E communication can be compromised without user awareness permitting ongoing communication between two unaware parties to be monitored.
Both points (security vulnerability and user experience prioritization) can be true simultaneously. This is the root of all plausible deniability when it comes to installing vulnerabilities in technologies.
I don't see why we should care at all about WhatsApp's intentions with the change when the effects are so pernicious. Facebook et al. definitely do not deserve the benefit of our doubt anymore.
Regardless - you still haven't given a source for you original claim. "not deserving benefit of the doubt" does not qualify. If the linked article is in fact you source then in the future please do not exaggerate such claims as you have done. I would have expected a claim from the article to read (along with a link to the source!):
> WhatsApp have modified the protocol slightly auspiciously for user experience but this allows a third party attacker to intercept messages sent offline only alerting the sender after they have been disclosed.
You mean, no-longer-E2EE.
Who is your employer? It's not mentioned in your profile...
On the other side of the spectrum are people who won't just install some random app without due dilligence, make a pass on appified websites and don't care about how many messengers they have on the phone because it doesn't really matter anyway due to the reactive usage pattern. I suppose MZ is like that.
If he really wanted to that, he would have several phones with separate numbers for exploring other messaging apps as not to cross business and personal matters.
(2) Lugging multiple phones is clumsy enough that most people won't consider it, most CEOs, even more so. Two is somehow tolerable. And you need competitors' apps always available, to try things while you have an idea, and to easily compare.
He has tape over the camera of his own computer in Facebook HQ
No matter how you trust your software, some malware may want to activate it, especially at a high-value target like Zuckerberg (or Bezos, or Nadella, etc).
Alas, microphones are not as easy to deactivate.
Easier on desktops that don't have a built-in mic.
I use a mic with a hardware power switch.
If someone can access my camera and spy my unkept beard, why won't they also be able to access my keyboard and spy my main email account password?
Lots of young girls were being lured into installing malware and had their bedrooms recorded.
¹(Edit) You can't make this stuff up: https://support.apple.com/en-us/HT211148
That’s why eg. all Purism products with them have hardware kill switches (to physically disconnect them).
He might be just trying to experience Signal here and there, and see how to take something from it to facebook.
I don't think he is using this seriously.