Lawyers in a high-profile gender bias lawsuit against a giant Silicon Valley firm argued the woman behind the case was either an accomplished junior partner who was passed over for a promotion because of discrimination or a failure who sued to get a big payout as she was being shown the door.

Facebook CEO Mark Zuckerberg and other Silicon Valley leaders have formally launched a political group aimed at revamping immigration policy, boosting education and encouraging investment in scientific research.

When US President Barack Obama arrives at Facebook headquarters this week, he will be the first sitting head of state to visit the brick-and-mortar home of the social media powerhouse.