One example relating to OS X is that malware running as root can defeat anti-keylogger protections such as this: https://developer.apple.com/library/content/tec

One example relating to OS X is that malware running as root can defeat anti-keylogger protections such as this: https://developer.apple.com/library/content/technotes/tn2150/_index.html#//apple_ref/doc/uid/DTS10004249 https://developer.apple.com/library/content/technotes/tn2150... If you were running your web browser as root, and a malicious website used a vulnerability to drop some malware on your system, then it would have complete power to do what it liked without needing to escalate privilege using another vulnerability.