The keystone of Japan's internet culture, 2channel, is under threat from authorities, due to a drugs crackdown by Japanese metropolitan police.
While the Western world might have many sources for media related stories, in Japan, news can be traced back to the infamous bulletin boards. However, there's also a culture of drug sales on the site that has been the reason given for the recent investigation into the site and its owners.
In a similar fashion to the media copyright lobbyists that target file sharing websites, Japanese authorities are gunning for the owners of the website, claiming that because drug soliciting and sales are discussed on the bulletin board, which aren't speedily removed, they can be held responsible. Backing up this claim with action, police recently raided ten locations relating to 2ch and those that run it.
While the 2channel ‘drug posts' have been known for some time, it's only in the past couple of years that much interest has been shown by authorities. According to Kotaku, since 2010, the metropolitan police has demanded the site's owners delete all posts relating to drugs. While this hasn't always been complied with, it seems a little harsh to implicate the site's backers - purely based on the often heavily coded language, used by those initiating drugs deals.
However, the crackdown has been gathering pace recently due to the new appointment of Tateshi Higuchi, as the new superintendent general of the Tokyo metropolitan police. He apparently considers 2ch to be a "den of iniquity."
While it seems likely that a complete shutdown would simply see users move elsewhere, the end of 2chan would create a significant void in Japanese internet culture, since it makes up such a huge portion of it.