A brief history of Uber scandals

Michigan resident Jason Dalton, the alleged shooter in a spree Saturday night that resulted in six deaths and two injuries, is 45 years old and had worked as an insurance salesman for Progressive. He was also an Uber driver. Amidst his shooting, Dalton reportedly picked up Uber riders in Kalamazoo, Mich.

Uber is playing defense now, with chief security officer Joe Sullivan saying on Tuesday: "No background check would have flagged and anticipated this situation." Still, the company has acknowledged that Dalton passed its background check, and also that it received complaints about Dalton hours before the shooting.

The event has raised obvious questions about Uber's safety measures for passengers and its process for approving drivers, who are not considered "employees" but contractors. They are questions that have been raised time and again as Uber has been in the news for the wrong reasons, and they are questions that a P.R. statement is unlikely to put to rest. This is the latest in a long line of scandals, missteps, and criminal activity associated with the app. Earlier this month, Uber spent nearly $30 million to settle two lawsuits over misleading customers regarding its safety measures.

But Uber continues to raise venture capital at soaring valuations: In July, the company closed a new round of more than $1 billion, bringing its valuation to more than $50 billion and leap-frogging Xiaomi, the Chinese smartphone maker, as the world's highest-valued tech "unicorn." (Airbnb, Snapchat, Palantir and other companies valued at more than $10 billion are now called "decacorns," but at $50 billion, Uber is a lone "quinticorn." In December, tech outlets reported Uber is seeking another couple billion in funding that would value it above $60 billion.) The company is like Donald Trump, in a way: Seemingly no amount of bad press can slow its momentum. The app now delivers an average 2 million rides every day.

From passengers being raped by Uber drivers, to the app implementing surge pricing during a hostage situation, to a senior executive suggesting the company dig up dirt on journalists, here are just some of the worst moments the six-year-old company has weathered.

December 2013: Uber driver hits a family, killing one

An Uber driver in San Francisco, Syed Muzaffar, struck a family in a crosswalk, killing a 6-year-old child. The family sued Uber for wrongful death, and the company at first denied responsibility because Muzaffar was in between fares at the time of the accident. The accident was the first to ignite a still-ongoing debate over whether Uber can be held accountable for its drivers, who are contractors, not employees. Last year, Uber settled with the family for an undisclosed sum.