SMS messages, for example, lack end-to-end encryption. Furthermore, given the fluctuating prices of data and text plans over the years, it may now be more expensive to send an SMS message than a Signal message.
“We’ve heard repeatedly from people who thought the SMS messages they were sending were Signal messages, only to discover that they were using SMS and being charged by their telecom provider,” Signal writes in a blog post. “This is a terrible experience with real ramifications.”
