Earlier today, Google experienced a rather significant glitch: All search results showed the “This site may harm your computer.” warning.
Normally this warning does a decent job of highlighting common, major sources of malware (and other unwanted things). Google reasonably disables potentially harmful links, and redirects to an intermediary page that (a) provides more information, and (b) requires you to copy + paste the address if you want to continue. It’s not perfect, but it’s another decent layer. So normally: if you see this warning you should pay attention.
For quite some time this morning, though, Google search was basically broken. The warning mistakenly showed up for all sites – which disabled clicking through to search results, cached copies of the pages, and essentially all of the usefulness of the search.
Google has since fixed the problem, but a screenshot is provided above for posterity.
UPDATE: It seems there is a lot of confusion about this on the Internet. To clarify:
The glitch was not caused by an infection on your computer. The problem was on Google’s end, and affected (seemingly) everyone.
If you are still seeing search results pages with all of the links marked as potentially harmful, try clearing your browser’s cache and refreshing the page.