FILE PHOTO: Facebook Founder and CEO Zuckerberg speaks in San Jose
INTERNATIONAL - Facebook chief executive Mark Zuckerberg broke his silence on the crisis over political advertising firm Cambridge Analytica’s access to user data on the social network, outlining concrete steps the company is taking to make sure such a leak doesn’t happen again.

The billionaire finally spoke in a series of media interviews, and a blog post, promising to probe the extent to which “rogue apps” are harvesting sensitive data on the social network. Zuckerberg told CNN that Facebook would inform every one of its two billion-plus users that may have had their personal data compromised.

“I’ve been working to understand exactly what happened and how to make sure this doesn’t happen again,” Zuckerberg wrote in a post on his Facebook profile page. “I promise you we’ll work through this and build a better service over the long term.”

By pledging to investigate whether Cambridge Analytica still holds the information it obtained from a third-party app creator, and broadening the probe to other developers that may have run afoul of Facebook’s rules, Zuckerberg took a step in the right direction, according to lawmakers, investors and users.

But it wasn’t enough to end the criticism - some remained sceptical the company is doing enough.

“This isn’t going to cut it,” said David Cicilline, a Democratic US representative from Rhode Island, in a Facebook response. “Mark Zuckerberg needs to testify before Congress.”

That sentiment was echoed by other lawmakers in the US and Europe.

Antonio Tajani, the president of the European Parliament, said in a Twitter post that many questions remain unanswered.

“I look forward to him giving further explanations before the elected representatives of more than 500 million European citizens,” Tajani said.

German Justice Minister Katarina Barley said she would ask Facebook officials to provide an explanation in person.

Speaking to UK media, Matt Hancock, a senior UK lawmaker, said: “It shouldn’t be for a company to decide what is the appropriate balance between privacy and innovation. The big tech companies need to abide by the law and we’re strengthening the law.”

Officials met privately with House Energy and Commerce Committee staffers from both sides of the political aisle for nearly two hours on Wednesday, according to two people who attended the meeting.

One main question was whether there might be others - including other “bad actors” - who might have had access to the same data that Cambridge Analytica obtained from more than 50 million Facebook profiles.

Staffers, speaking on condition that they not be identified, said the officials acknowledged that the company did know how widely disseminated that information might be, or how many copies were made.

Zuckerberg said he was “open” to testifying before Congress, if he’s the right person to provide the information lawmakers need. But he stopped short of committing to appear.

Zuckerberg’s solutions focused solely on the outside developers that have accessed Facebook user details through login tools.

“They’re not recognising that they have systemic problems,” Brian Wieser, an analyst at Pivotal Research, said.

“These are just the problems we know about, but they have ongoing problems managing different parts of their business,” Wieser said

The company came up with steps to resolve the developer problems, but “to garner full appreciation from the public and the market, there should be greater emphasis on why it occurred in the first place,” said James Cakmak, an analyst at Monness Crespi Hardt & Co.

Zuckerberg waited several days to respond to news reports, even as the furore grew.

Following the calls from lawmakers, there have been broader questions about how Facebook’s management is handling the fallout.