The Japanese Digital Comics Association, along with several other Japanese trade groups (for books and magazines) is threatening to sue Apple over pirated content in the iTunes App Store, according to the Wall Street Journal. 

Apple argues that it takes down content when it finds out it’s pirated but that it’s impossible to know that the content is pirated before it puts it up.  To us, that seems a little hard to believe when Apple is checking every app for inappropriate content.  The Japanese trade associations apparently agree; their release called Apple’s claim “a wholly unconvincing explanation.”