Users adding an incorrect user by mistake to a group is no reflection at all on the security of any app. This happens across all apps, as the user is the issue, not the app.
I had long ago deleted the WhatsApp app off my phone, mainly because of its metadata collection, and the sharing of that data with their upstream ‘partners’ including Facebook and others. This is clearly stated in WhatsApp’s T&C’s.
‘In a statement, a WhatsApp spokesman said it relies on metadata to prevent spam and “keep the service safe from abuse”.’ This is just not true, in that this is not the reason why WhatsApp collects metadata — their T&C’s state it is to be shared elsewhere.
Yes, both Signal and WhatsApp keep the message content secure, and use the same encryption protocol. But WhatsApp is also collecting your location continuously, when you message who, for how long, when you wake up, when you go to sleep, where you shop, etc (and of course shares this with your consent).
This is not Signal’s business model, nor do they obtain your consent to share this data. WhatsApp/Instagram/Facebook are all about targeting users for advertisers, and sharing data for that targeting (and of course being US owned they have to share that data under the CLOUD and Patriot Acts with the US government as well when requested).
What came out of the US Congressional hearing this week was also interesting to hear — the CIA have Signal installed on their desktops, and they use Signal themselves.
I’m not saying at all that Signal is perfect, as it still requires a verified phone number. So the user is still always identifiable (unlike other messengers such as Threema, SimpleX, Matrix, Session, etc).
It is about what data is collected, and what data is shared with anyone outside of the organisation. Between WhatsApp and Signal, Signal is the clear winner here.
For this reason, there is no WhatsApp app on my mobile phone. If organisations want to ensure better privacy, they should use Signal (like the CIA does) or go a step further and self-host a service like Matrix on their premises where they fully control the data as well as the user access verification.
WhatsApp was a very good app (I used to use it) before they got bought out by Facebook, and it is that business model that has ruined it.
See https://techcentral.co.za/signal-vs-whatsapp-messaging-app-war/261341