You’ve almost certainly heard, by now, that someone at search giant Google made a tiny little mistake in routine maintenance this past weekend which resulted in a huge uproar.

In it’s simplest terms, an update to a ‘dangerous Web sites’ list generated by another party, was installed improperly at Google resulting in all Google search results being tagged potentially hazardous to visit.

As Google’s VP of Search Products and User Experience, Marissa Mayer, wrote in the Official Google Blog late Saturday, January 31:

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. We do this to protect our users against visiting sites that could harm their computers. We maintain a list of such sites through both manual and automated methods. We work with a non-profit called StopBadware.org to come up with criteria for maintaining this list, and to provide simple processes for webmasters to remove their site from the list.

We periodically update that list and released one such update to the site this morning. 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, our on-call site reliability team found the problem quickly and reverted the file. Since we push these updates in a staggered and rolling fashion, the errors began appearing between 6:27 a.m. and 6:40 a.m. and began disappearing between 7:10 and 7:25 a.m., so the duration of the problem for any particular user was approximately 40 minutes.

The problem persisted for less than an hour this past Saturday morning but generated a lot of confusion.

Industry observers say the incident is a prime example of the dangers of dependence on a single vendor or service provider for any vital product of service.