It has been an exciting week for Signal Messenger - between an endorsement from the world's richest person and a 38% surge in downloads, some say the encrypted messaging app is having its moment.

This, after WhatsApp said it is tweaking its terms of use and privacy policy to share significantly more user data with Facebook. And there isn't an opt-out option - you either accept the terms or stop using the app altogether.

But Signal and WhatsApp do have a common thread - their creator Brian Acton, who left the world's largest messaging service after a rift with Facebook CEO Mark Zuckerberg over monetising the app. His early exit cost him $850 million.

Exit from WhatsApp

Facebook acquired WhatsApp in February 2014 for close to $22 billion, making Acton a billionaire. But he left less than four years later, in September 2017, due to his strained ties with Zuckerberg. The Facebook CEO wanted to monetise WhatsApp using targeting ads and commercial messaging, according to a Forbes report.

Ten months after his departure, the Cambridge Analytica scandal unfolded. Acton tweeted, "It is time. #deletefacebook". He hasn't tweeted since.

It is time. #deletefacebook— Brian Acton (@brianacton) 1521586819000
The creation of Signal

Acton took his motto of "no ads, no games, no gimmicks" at WhatsApp and created Signal Messenger Llc with Moxie Marlinspike of Open Whisper Systems in January 2018. The two-year-old app is entirely funded by grants and donation, which - according to Twitter CEO Jack Dorsey - is how such services should be built.

Signal today is considered the gold standard for privacy by journalists to whistleblowers. According to its website, American whistleblower Edward Snowden is a loyalist and uses the app every day.