Brian Acton joined thousands of people in taking to Twitter with the hashtag "#DeleteFacebook" trending on the micro-blogging site, amid the investigation into Facebook's breach of data this time last year.
He wrote at the time: "It is time. #deletefacebook (sic)"
Acton left WhatsApp and Facebook in 2017, after he sold the app to Mark Zuckerberg for $19 billion in 2014. He now works at competitor Signal, which puts privacy first.
Speaking at Stanford University recently, he reiterated: "These companies are not equipped to make these decisions.
"And we give them the power. That's the bad part. We buy their products. We sign up for these websites. Delete Facebook, right?"
On his decision to leave, he added: "You go back to this Silicon Valley culture and people say, 'Well, could you have not sold?' and the answer is no.
"I had 50 employees, and I had to think about them and the money they would make from this sale.
"I had to think about our investors and I had to think about my minority stake.
"I didn't have the full clout to say no if I wanted to."
The iconic social networking site came under fire after it was revealed that the data of millions of Facebook users had been harvested.
The app faced criticism from a number of high-profile politicians, including British Prime Minister Theresa May, who admitted to being concerned by the situation.
Meanwhile, Facebook founder Mark Zuckerberg faced increasing pressure to open up about the social network site's conduct.
The company was accused of failing to properly inform users that their profile data may have been obtained and then kept by Cambridge Analytica.