Former Sankei Newspaper journalist Sumio Yamagiwa, organized an online campaign to tweet #マスコミ断罪 [ja], a hashtag criticising Japanese mass media for its biased reporting. The hashtag was a trending topic amongst Japanese twitter users, roughly around 9 PM to 11 PM on December 12, 2012
Screenshot taken from twipple, twitter analytic service showing hashtag #マスコミ断罪 [convict mass media] trending
Some of the tweets accused the mass media of inventing Korean “comfort women“, and some included xenophobic hate speech calling the mass media unpatriotic because they are pushing Korean programs. A curated list of tweets are available in Japanese here.