Facebook was targeted by 'sophisticated' hackers
16 February 2013 Last updated at 05:38 GMT
Facebook has revealed it was the target of a "sophisticated attack" by hackers last month, but found no evidence any user data had been compromised.
The US-based social network said that the attack occurred when employees visited a mobile developer website "that was compromised".
Facebook said in a blog post that it was not the only company to have been attacked in this way.
Alastair Leithead reports from Los Angeles.