Facebook CEO says his own data was shared by Cambridge Analytica

“Every time that someone chooses to share something on Facebook … there is a control. Right there. Not buried in the settings somewhere but right there,” the 33-year-old internet magnate told the US House of Representatives Energy and Commerce Committee.

Once again wearing a dark suit instead of his usual gray T-shirt, the hearing is Zuckerberg’s second in two days. On Tuesday, he took questions for nearly five hours in a US Senate hearing without making any further promises to support new legislation or change how the social network does business, foiling attempts by senators to pin him down.

Investors were impressed with his initial performance. Shares in Facebook posted their biggest daily gain in nearly two years on Tuesday, closing up 4.5 percent. They were down 0.7 percent in early trading on Wednesday.

Facebook has been consumed by turmoil for nearly a month, since it came to light that millions of users’ personal information was wrongly harvested from the website by Cambridge Analytica, a political consultancy that has counted US President Donald Trump’s election campaign among its clients.

Zuckerberg faced broad concerns from members of Congress about how Facebook shares user data.

“How can consumers have control over their data when Facebook does not have control over the data?” asked Representative Frank Pallone of New Jersey, the ranking Democrat on the Energy and Commerce committee.

The latest estimate of affected users is up to 87 million.

Patience with the social network had already worn thin among users, advertisers and investors after the company said last year that Russia used Facebook for years to try to sway US politics, an allegation Moscow denies.

Lawmakers have sought assurances that Facebook can effectively police itself, and few came away from Tuesday’s hearing expressing confidence in the social network.