If you did a Google search between 6:30 a.m. Pacific Standard Time and 7:25 a.m. PST this morning, you likely saw that the message "This site may harm your computer" accompanied each and every search result. This was clearly an error, and Google have apologised for the inconvenience caused to their users.
What happened? Very simply, human error. Google flags search results with the message "This site may harm your computer" if the site is known to install malicious software in the background or otherwise surreptitiously. They do this to protect users against visiting sites that could harm their computers.
Unfortunately (and here's the human error), the URL of '/' was mistakenly checked in as a value to the file and '/' expands to all URLs. Fortunately, Google's on-call site reliability team found the problem quickly and reverted the file. The duration of the problem for any particular user was approximately 40 minutes.
Overload by Valenberg
1 hour ago