Disgruntled drivers and 'cultural challenges': Uber admits to its biggest risk factors

Company issues warnings over workplace environment in public disclosures filed to the SEC

When Uber filed the paperwork for its initial public offering on Thursday, the quintessential bad boy startup signaled to the world that it was ready to grow up. In a letter to potential investors, the CEO, Dara Khosrowshahi, acknowledged the "greater responsibilities" the company will take on once it goes public, and promised to act with "passion, humility, and integrity".

But references to the company's checkered past are littered throughout the more than 300 pages of public disclosures filed to the Securities and Exchange Commission. Here's a rundown of some of the biggest "risk factors" from Uber's past that may come back to haunt its $100bn future: