Brian Acton, the cofounder of WhatsApp, renewed calls for people to delete Facebook on Wednesday while speaking on a panel at Stanford University.

According to Buzzfeed News, Acton said of Facebook: “We give them the power. That’s the bad part. We buy their products. We sign up for these websites. Delete Facebook, right?”

Acton sold WhatsApp to Facebook in October 2014 for $19 billion but told Forbes that he left the company at the end of 2017 as Facebook considered introducing ads to the WhatsApp platform and offering businesses a direct channel to communicate with WhatsApp users.

Brian Acton, the cofounder of WhatsApp, urged students at Stanford University to delete their Facebook accounts on Wednesday as he defended his reasons for selling his instant messaging startup to Mark Zuckerberg for $19 billion in 2014, according to Buzzfeed News.

Acton, 47, made his comments on a panel that also involved Ellora Israni, a former Facebook software engineer. It is only the second time he has spoken out publicly about his differences with Facebook.

According to Buzzfeed News, Acton said of Facebook: “We give them the power. That’s the bad part. We buy their products. We sign up for these websites. Delete Facebook, right?”

Acton sold WhatsApp to Facebook in October 2014 for $US19 billion but told Forbes that he left the company at the end of 2017 as Facebook considered introducing ads to the WhatsApp platform and offering businesses a direct channel to communicate with WhatsApp users.

The former Yahoo! employee, who is also a Stanford alum, first started trying to convince people to delete Facebook in March 2018 when he tweeted: “It is time. #deletefacebook”

Facebook also owns Instagram and Messenger so its global reach is enormous, with over a billion people using the platforms.

Read more: Facebook and Instagram go down for hours in major outage — and it says it's not being DDoS attacked

While Instagram has surged in popularity in recent years, Facebook is battling to keep younger users engaged and its growth has slowed considerably since the early days.

On the WhatsApp acquisition, Acton said during Wednesday’s panel: “I had 50 employees and I had to think about them and the money they would make from this sale.”

He continued: “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 comments were made as Facebook, WhatsApp and Instagram all experienced global outages.