Facebook has apologized for the data breach that was revealed last week. CEO Mark Zuckerberg took out full-page adverts in newspapers in the UK and US. He was being criticized for being too slow to respond to news of the breach. Data on up to 50 million users was used by a group of consultants called Cambridge Analytica (CA). CA is accused of using the data to benefit Donald Trump's presidential campaign. Zuckerberg said: "This was a breach of trust, and I am sorry....We're now taking steps to make sure this doesn't happen again." The apology made no mention of CA.
Mr Zuckerberg said Facebook should have done more to protect data from being exploited. There are reports that Facebook was warned about its weak data protection back in 2011. Mr Zuckerberg outlined the actions Facebook would now take. He said: "We're investigating every single app that had access to large amounts of data...We expect there are others. And when we find them, we will ban them and tell everyone affected." The value of Facebook fell by $75 billion this week. Many users have been abandoning their Facebook pages, in calls to #deletefacebook.