text: Uber has poached Facebook's security chief Joe Sullivan in an attempt to double down on rapidly escalating safety concerns. The $40 billion taxi service has been plagued by serious accusations of failing to vet its drivers. Lawsuits have been brought against Uber in San Francisco and Los Angeles. A New Delhi driver was accused of raping a passenger in December. This week in Denver, a driver tried and failed to break into a passenger's home. And in London, a woman was allegedly asked to perform oral sex on her driver. These claims, among others, follow a data leak last May, which saw the details of 50,000 current and former drivers released into the public domain. It is hoped Sullivan, the first federal prosecutor to specialize in high-technology crime, can protect Uber from potentially crippling ramifications. Lifeline? Joe Sullivan, 46, will leave his role as Facebook's security chief to help Uber defend safety concerns . There were three high-profile assault cases involving Uber drivers in December 2014. An Indian woman said her driver raped her in New Delhi, leading to outcries and a temporary ban of Uber in that city. It came days after a driver was charged in Boston with raping a young woman. The same week, a woman in London revealed that she was offered £20 credit from Uber after one of its drivers allegedly sexually harassed her during a cab ride. This week in Denver an UberX driver was arrested after he dropped a passenger off at the airport before allegedly driving back to her house, and trying to break in. The cities of San Francisco and Los Angeles are both suing the company for 'misleading the public' by failing to conduct thorough backgrounds checks. The firm's first security chief, he brings with him an extensive portfolio of experience in cyber security and privacy. He spent two decades tackling cyber crime security in the private and public sector before joining the Justice Department. Cases included child protection, bank privacy, and digital strands of 9/11 investigations. Since, he has headed up the security departments at eBay, PayPal, and Facebook. Though his experience lies in digital protection, Uber CEO Travis Kalanick has also entrusted the 46-year-old with tackling physical security. Sullivan's role will involve liaising with city and state governments around the world as the firm rapidly expands. Announcing the hire in a blog post on Thursday Kalanick wrote: 'We are both in cyberspace and on city streets all at once; a bridge between bits and atoms. 'And as we get into tens of millions of rides a week, we continue to challenge ourselves to do even better when it comes to safety and data security.' He added: 'This is a challenge where I get to take what makes Silicon Valley special and apply it to a product that directly impacts people's lives everyday as they move around the world's cities.' Allegations: The rapidly-expanding mobile taxi service has been plagued by claims that drivers are not vetted . Looking forward: The $40 billion firm's CEO Travis Kalanick announced the news in a blog post on Friday . There were three high-profile assault cases involving Uber drivers in December 2014. An Indian woman said her driver raped her in New Delhi, leading to outcries and a temporary ban of Uber in that city. It came days after a driver was charged in Boston with raping a young woman. The same week, a woman in London revealed that she was offered £20 credit from Uber after one of its drivers allegedly sexually harassed her during a cab ride. This week in Denver an UberX driver was arrested after he allegedly dropped a passenger off at the airport before turning around, driving back to her house, and trying to break in. The cities of San Francisco and Los Angeles are both suing the company for 'misleading the public' by failing to conduct thorough backgrounds checks.
target: Joe Sullivan, 46, was the first federal prosecutor specializing in high-tech .
  He has worked in security for eBay, PayPal and Facebook .
  As Uber's first security chief he will attempt to curb growing claims .
  $40bn taxi firm accused of not adequately vetting drivers .
  India driver accused of rape, Denver driver of burglary, London driver of sexual assault .