New Delhi, April 11: Facebook CEO Mark Zuckerberg has admitted in his testimony before the US Senate’s Commerce & Judiciary Committee that his own data was mined by Cambridge Analytica. On Day 2 of his testimony, Zuckerberg was answering queries on user privacy and what they did with the data collected.

He said that everytime someone shared data, it was clear who they were sharing it with. He explained that there was a difference between surveillance and Facebook. He said, “Users can choose to leave Facebook when they want. They can delete their data Facebook data if they want to.” He said Facebook was limiting the data it collected and added that they were working on changing the default settings for the better protection of privacy. “We have changed a lot of the way our platform works so that developers cannot access so much information,” he is reported to have told the committee.

To a question on if he could give make a commitment over changing default settings so as to minimise collection of user data, the Facebook CEO could not give a definitive answer and said, “It is a complicated issue…”

As to whether Facebook would offer to its users a blanket opt-in for sharing data with third-party app developers, Zuckerberg replied in the affirmative and said that that was how the platform worked.  When he was asked if criminals or terrorist groups had deleted user data, he said they were not aware of any group involved in such activity where the data was allegedly sold.

In his testimony on Day 1, Zuckerberg had said that he took personal responsibility for the data breach. He said his company would do everything possible to ensure that fair elections took place across the globe. He also explained that WhatsApp was fully encrypted so messages on that app could not be read by Facebook.