How do you know that there is not a back door in WhatsApp?

Presumption of innocence, or do you have seen any evidence to prove it exist, besides Durov's shit from time to time?

In the context of privacy, you can pretty much assume every black box is compromised. With Telegram this black box is the server (the client is open source); with WhatsApp, it's the client. I suppose there's threat models where WA still wins, but knowing it's owned by Meta, I have a hard time imagining what such a threat model would look like.

Is the Whatsapp client really a black box? APKs are fairly straightforward to decompile back to Small or a reasonable approximation of Java, or people on rooted devices can hook it with Frida. Of course source code would be better, but it would be pretty brazen to stick a backdoor in an app store release. App versions for popular apps get archived by numerous third-party sites, so even a temporary backdoor in one specific version would be archived forever. That would be putting their reputation and billions of dollars on the line.

Non-E2E with black box server code like Telegram is far more concerning, in my opinion. With a system like that, it would be trivial to backdoor and leave behind no evidence after the fact.

Which reputation? The reputation of a company that doesn't care about privacy at all and we t through dozens of privacy scandals?

Seems like someone doesn't like the truth

It is very difficult to find a backdoor even in the open source code, in megabytes of closed source code it is nearly impossible.

> That would be putting their reputation

Does Facebook have any reputation left?

> Does Facebook have any reputation left?

Most people still think of WhatsApp and Facebook as separate. For a while, WhatsApp displayed a Facebook logo for a second whenever it started (and given how Android works, opening WhatsApp does not necessarily mean starting it, most of the time it just switches to an already started process), but even that does not happen anymore, since it was replaced by a "Meta" logo (and most people do not associate "Meta" with Facebook).

Telegram has more reputation that Meta.

bullied how? it's easier to get bullied when you have an office space, they harass your employees. it's easier to get bullied when you sell products/service, they stop your money flow. what/how do you envision them bullying Signal?

> ... what/how do you envision them bullying Signal?

I guess, by outlawing them. Think of the collateral damage. For ex, unavailability of Signal means MobileCoins in wallets of its Indian users become inaccessible (theoretically, since Signal is a non-custodial wallet) if they don't get it out in time before the ban, so there's something for Signal to think about.