You can start with The Uber files, which "is a global investigation into a trove of 124,000 confidential documents from the tech company that were leaked to the Guardian."

Summary

Uber broke laws, duped police and secretly lobbied governments, leak reveals

Some examples:

• The cache of more than 124,000 internal Uber files lays bare the ethically questionable practices through which the company barged its way into new markets, often where existing laws or regulations made its operations illegal, before lobbying aggressively for those same laws or regulations to be altered to accommodate it. Read here
• Senior executives at Uber ordered the use of a “kill switch” to prevent police and regulators from accessing sensitive data during raids on its offices in at least six countries. Read here
• Two of Barack Obama’s most senior presidential campaign advisers, David Plouffe and Jim Messina, discussed helping Uber get to access leaders, officials and diplomats. Read here
• At least six UK government ministers, including the then chancellor, George Osborne, and the future health secretary Matt Hancock, did not declare secret meetings at which they were lobbied by Uber. Read here
• The inside story of how Uber used its connections to the Conservative party to lobby Boris Johnson in a rearguard effort to stop Transport for London introducing new regulations. Read here
• One of Uber’s top executives quit amid questions for the company about whether its European operations were structured in a way that avoided tax. Read here
• Uber secretly hired a political operative linked to Russian oligarchs allegedly aligned with Vladimir Putin in an attempt to secure its place in the Russian market, despite internal bribery concerns. Read here

[...]

As Bonus some older articles about their overall ethics and practices:

• Harvard Business Review: Uber Can’t Be Fixed - It’s Time for Regulators to Shut It Down
• NY Times: How Uber Deceives the Authorities Worldwide paywalled | archived article
• The Verge This is Uber's playbook for sabotaging Lyft
• BuzzFeed: Uber Executive Suggests Digging Up Dirt On Journalists
• Business Insider: Uber has lost its licence to operate in London .. as "Uber was not "fit and proper" to hold a licence"
• Business Insider: France was right to punish Uber, according to a top European legal adviser | archived article