Not entirely inert, but it takes a lot to get them to sue. They tend to go with the flow because tracking down and bringing all of the copyright infringers in Japan to court would be a very exhausting job, much less those in other countries. They tend to just chalk it up as a form of advertising.
US companies tend to be a lot more proactive about their licensing rights. For example, Funimation recently came down very, very hard on a fansubbing group for releasing shows they had licenses for, even though Funimation hadn't even announced release dates for the shows yet. Not just legal action, either. They contacted the web host for the subber's web page and had them suspend the site.


