In a recent interview with Forbes, WhatsApp co-founder Brian Acton explained why he decided to leave Facebook and $850 million on the table: there was a disagreement over how Facebook should monetize WhatsApp, the chat service Facebook acquired in 2014.

Acton told Forbes that Mark Zuckerberg and other Facebook executives wanted to begin targeting ads at users and selling business analytics tools, two plans that Acton didn't agree with. "At the end of the day, I sold my company," Acton told Forbes. "I sold my users' privacy to a larger benefit. I made a choice and a compromise. I live with that every day."

In March, when Facebook was at the center of a scandal involving the exposure of private user data, Acton tweeted "It is time. #deletefacebook." His fellow WhatsApp co-founder, Jan Koum, departed Facebook in April.

@brianacton: It is time. #deletefacebook

On Monday, Instagram co-founders Kevin Systrom and Mike Krieger resigned from Facebook. Systrom and Krieger did not have "philosophical misalignments," with Facebook like Acton and Koum did, Systrom told WSJ Magazine.

Facebook was not immediately available to comment.

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