…one Yasuhiro Kawaguchi was arrested yesterday on suspicion of “saving a virus on his computer,” though the story suggests distribution of malware too…

[Update: Michael St Nietzel also pointed out that there's an issue with installers that verify a checksum before installation. In fact, this is a special case of an issue I may not have made completely clear before: unless this approach is combined with some form of whitelisting, there has to be some way of reversing the modification