Facebook CEO Mark Zuckerberg, in his first comments since a user privacy crisis engulfed his company, has admitted Facebook made mistakes.

News broke last Saturday (Friday US time) that Cambridge Analytica, a UK-based political data-analytics firm hired by the 2016 Trump campaign, got its hands on data for 50 million Facebook users – without the users’ knowledge or consent.

“I’ve been working to understand exactly what happened and how to make sure this doesn’t happen again,” Mr Zuckerberg wrote in a blog post Wednesday.

“The good news is that the most important actions to prevent this from happening again today we have already taken years ago. But we also made mistakes, there’s more to do, and we need to step up and do it.”

Mr Zuckerberg promised Facebook would investigate all apps that had access to “large amounts of information” before the company changed its platform to reduce data access in 2014.

Second, he pledged to restrict developers’ data access “even further to prevent other kinds of abuse”.

For example, it will remove developers’ access to user data if you haven’t used their app in three months.

Third, Facebook will display a tool at the top of the News Feed with apps users have used and an easy way to revoke those apps’ permissions to your data.

Facebook says the researcher that supplied the data to Cambridge Analytica, going back to 2013, lied to the company and violated its policies.

The company barred Cambridge Analytica and its parent company from using its platform, and also says it no longer allows third-party apps to captured data the way that was done in this case.

“This was a breach of trust between [researcher Aleksandr] Kogan, Cambridge Analytica and Facebook,” Mr Zuckerberg wrote.

“But it was also a breach of trust between Facebook and the people who share their data with us and expect us to protect it. We need to fix that.”

The scandal has drawn renewed scrutiny on Facebook’s data-handling practices from lawmakers and regulators, led some users to call for a boycott (via the hashtag #DeleteFacebook) and prompted lawsuits from shareholders and users.

It ignited a two-day selloff of Facebook stock, before shares recovered some ground Wednesday.

Gold Coast Games organisers dump data mining plan

The controversy saw Commonwealth Games organisers dump a plan to mine data from Commonwealth Games visitors who use free high speed wi-fi.

Originally the council was going to require people to use their Facebook login if they wanted fast wi-fi.

Council told the ABC it would collect some data from users’ Facebook pages including their age, nationality and gender.

Mayor Tom Tate said council would use it to “monitor” where people came from.

But on Thursday Councillor Hermann Vorster told media the council now cannot trust Facebook.

“Like most people around the planet, we are shocked to learn Facebook can’t be responsible for its own data in the first place,” he said.

“So what council will do, while Facebook is getting its house in order, is ensure the feature is removed from the login screen.”

-with AAP and ABC