A Signal és a Viber szerintem komolytalan onnantól, hogy csak telefonszám alapján lehet a másikkal felvenni a kapcsolatot, bár én eleve nem tartom szerencsésnek azt, ha e2ee az egyetlen opció. Ezen felül a Viber closed-source, amely nem lenne probléma független audittel, ami viszont afaik nincs. Az adatkezelési irányelveik is visszásak.
(a) Registration and Account Information: When you use our various Services you voluntarily give us personal information (e.g., name, email, birth date, age, phone number and, when necessary, billing information) and you are not anonymous to us. That means your name and photo (if you choose to provide them) will be visible to other Viber users. When you install the Viber App, you’ll also be asked to allow us access to your mobile device’s address book. A copy of the phone numbers and names of all your contacts (whether they’re Viber members or not – but only name and phone number) will be collected and stored on our servers in order for us to be able to enable you and your contacts to connect.