Do you blindly trust GitHub your private source code?

Would you keep your (let's say) 1 billion dollar private codebase to a third-party company like GitHub (Microsoft) or Bitbucket (Atlassian)? What makes you sleep at night and not going paranoid about your intellectual property that may get stolen and sold secretly sometime by either hackers, rogue employees or even the actual company? Are there any big companies that keep their whole codebase on these providers or they choose to store code at their own data centers?