Google has pushed out the first Penguin update to its webspam fighting algorithm since Penguin was launched on April 24th. Google's head of spam Matt Cutts announced the news on Twitter, calling it a "data refresh" that impacts less than one-tenth of a percent of English-language searches.
Minor weather report: We pushed 1st Penguin algo data refresh an hour ago. Affects <0.1% of English searches. Context: goo.gl/4f7Pq
-- Matt Cutts (@mattcutts) May 26, 2012
Google has described Penguin as an algorithm change that's aimed at webspam and, more specifically, "sites that we believe are violating Google's quality guidelines."
Cutts recently on Google Webmaster answered to a question "What happens if I link to a good page that later becomes spammy?"
Site A links to Site B because Site B has content that would be useful to Site A's end users, and Google indexes the appropriate page. After the page is indexed, Site B's content changes and becomes spammy. Does Site A incur a penalty in this case? MrTVTL, Toronto