Facebook bought WhatsApp for $16 billion back in 2014 from its co-founders — Jan Koum and Brian Acton. Koum continues to lead the company under Facebook, while Acton quit earlier this year to start his own foundation. He made a post on Twitter today, telling his followers to delete Facebook. “It is time,” Acton wrote, adding the hashtag #deletefacebook.

— Brian Acton (@brianacton) March 20, 2018 Brian’s tweet came after a hard-five-day period for Facebook after reports emerged that a political data analysis company Cambridge Analytica accessed 50 million Facebook users’ data without their permission. After the revelations about Cambridge Analytica’s misuse of user data, Facebook announced two days ago that it had hired a digital forensics firm to investigate the data leak. However, it is unclear as of now whether Acton’s tweet about Facebook is targeted at this data leak case or he is hinting towards any other issue. As reported by the Verge, last month Acton invested $50 million into Signal, which is an alternative messaging app to WhatsApp. Notably, Acton is not the first former Facebook employee to express unease about the company after leaving it. As per the Verge’s report, last year former head of growth Chamath Palihapitiya also said about Facebook, “we have created tools that are ripping apart the social fabric of how society works.” Other former executives to express regrets over Facebook include Sean Parker, Justin Rosenstein, and Roger McNamee.