Google has rolled out yet another update to their troubled search engine algorithms. This update, belatedly dubbed “Penguin”, was supposedly targeted towards sites which engaged in spammy SEO tactics, but instead it appears to have penalized a wide range of legitimate and high quality web sites.

Some of the biggest losers are sites many ByteGuide readers know well, including:

comcast.com is one of the largest cable television companies and Internet service providers in the world. Comcast lost 31% of their visibility in the Google’s rankings.

dslreports.com is one of our favorite sites and home to the best Internet speed test on the web. DSLReports lost 49% of their visibility in Google.

appbrain.com is one of the best sites to find applications for Google’s Android platform. Google visibility for AppBrain fell 34% during this update.

ghacks.net is an excellent source for tech news. GHacks SEO visibility in Google fell 41%.

robtex.com provides very useful (and free) tools for network engineers. Robtex was relatively lucky, losing only 22% of their visibility from Google’s latest debacle.

dictionary.com is a well known and high-quality dictionary.  Dictionary.com lost 42% of their search engine visibility in Google.

Google’s results have been growing steadily worse over the last few years, with a noticeably sharp drop in the last twelve months. Quality web sites have been pushed out of the results, only to be replaced with spam from Yahoo Answers, YouTube, and About.com.

The picture above is Google founder Sergey Brin wearing a dress.  Google should be far more embarrassed by the low-quality of their current search results than by any picture of Sergey in a dress.

Note: All SEO visibility numbers are from the wizards at SearchMetrics.