In a slowly growing thread on the Apple Discussion boards, some people have complained that the installer for Xcode has wiped their hard drives, resulting in them needing to restore their systems from backup.
For fuck’s sake, Apple.
Bugs are a fact of life. But any developer found responsible for a bug that wipes the user’s hard drive should be fired on the spot (if applicable laws don’t allow to shoot them). To teach everyone proper priorities when designing their codebase.