In the past, it was noticed that through bulk SMSes, investors were induced to invest in or purchase the stocks of certain listed companies. The gold standard of encryption, known as end-to-end encryption, where only the sender and person who receives the message are able to see it, is available on Telegram only when the Secret Chat function is enabled. Voice and video calls are also completely encrypted. Individual messages can be fully encrypted. But the user has to turn on that function. It's not automatic, as it is on Signal and WhatsApp. Such instructions could actually endanger people — citizens receive air strike warnings via smartphone alerts. "The argument from Telegram is, 'You should trust us because we tell you that we're trustworthy,'" Maréchal said. "It's really in the eye of the beholder whether that's something you want to buy into."
from kr