FILE - In this Nov. 19, 2016 file photo, Mark Zuckerberg, chairman and CEO of Facebook, waves at the CEO summit during the annual Asia Pacific Economic Cooperation (APEC) forum in Lima, Peru. A Hawaii Senate committee is scheduled to hear a bill that would force landowners into mediation before they are allowed to file lawsuits to acquire small parcels initially awarded to Hawaiian commoners during mid-19th century land reforms. The bill was introduced after Zuckerberg in late 2016 filed lawsuits to identify owners of 14 parcels interspersed within a 700-acre oceanfront estate he owns on Kauai. (AP Photo/Esteban Felix, File)
INTERNATIONAL - Facebook has said that the personal information of up to 87million users might have been improperly shared with political consultancy Cambridge Analytica, up from a previous news media estimate of more than 50million.

Chief executive Mark Zuckerberg said in a conference call with reporters on Wednesday that Facebook had not seen “any meaningful impact” on usage or ad sales since the scandal, although he added, “it’s not good” if people are unhappy with the company.

Shares rose more than 3percent after the bell.

Zuckerberg told reporters that he accepted blame for the data leak, which has angered users, advertisers and lawmakers, while also saying that he was still the right person to head the company he founded.

“When you’re building something like Facebook, that is unprecedented in the world, there are going to be things that you mess up,” Zuckerberg said, adding that the important thing was to learn from mistakes.

He said he was not aware of any discussions on the Facebook board about him stepping down.

He said he had not fired anyone over the scandal and did not plan to. “I’m not looking to throw anyone else under the bus for mistakes that we made here,” he said.

Facebook first acknowledged last month that personal information about millions of users wrongly ended up in the hands of Cambridge Analytica.

Zuckerberg will testify about the matter next Tuesday and Wednesday during two US congressional hearings.

London-based Cambridge Analytica, which has counted US President Donald Trump’s 2016 campaign among its clients, disputed Facebook’s estimate of affected users. On Wednesday it said on Twitter that it had received no more than 30million records from a researcher it hired to collect data about people on Facebook.

Zuckerberg, on the call with reporters, said Facebook should have done more to audit and oversee third-party app developers like the one that Cambridge Analytica hired in 2014.

“Knowing what I know today, clearly we should have done more,” he said.

Most of the up to 87million people whose data was shared with Cambridge Analytica were in the US, Facebook chief technology officer Mike Schroepfer wrote in a blog post.

Shares in Facebook closed down 0.6percent on Wednesday to $155.10 (R1839.80). They have tumbled more than 16percent since the Cambridge Analytica scandal broke.

The previous estimate of more than 50million Facebook users affected by the data leak came from two newspapers, the New York Times and London’s Observer, based on their investigations of Cambridge Analytica.

Zuckerberg said Facebook came to the higher estimate by looking at the number of people who had downloaded a personality quiz app created by Cambridge University academic Aleksandr Kogan, or about 270000 people, and then adding in the number of friends they had. Cambridge Analytica has said that it engaged Kogan “in good faith” to collect Facebook data.

The scandal has kicked off investigations by Britain’s Information Commissioner’s Office, Australia’s Privacy Commissioner and the US Federal Trade Commission and by some 37 US state attorneys-general.

Nigeria’s government will investigate allegations of improper involvement by Cambridge Analytica in that country’s 2007 and 2015 elections, a presidency spokesperson said on Monday.

- REUTERS