Japan has been the latest country publicized as being hit with the link network penalties by Google. Matt Cutts announced early this morning on Twitter that the web spam team in Japan has taken action against seven link networks over the last few months.
Cutts doesn't detail any more specifics about when the action was taken or which networks were hit. However, many of the Twitter replies made comments about which countries they hope Google would target next, including Pakistan, Sweden, and Russia.
The Japanese web spam team has been pretty active helping webmasters. They release frequent videos on Google's Webmaster Help YouTube channel, host their own Webmaster Office Hours and they also have their own Google Webmaster Central blog and Webmaster Troubleshooting page, designed to help webmasters investigate the problems they are having and the solutions they should utilize to solve them.
This is the latest in a long list of international link networks that Google has been penalizing, including Spain, Italy, Germany, and France.