Urm.. the opposite of someone's suggestion (which will remain anonymous) for me to post under more names... that'll teach me to not log out.

Good question and one to keep track of issues with the game MOD crowd. I think virus checking downloads is a standard practice and a dormant virus that gets out is a unwelcome possibility. I don't think however that our approach would necessarily be more virus-prone than any other MOD'able interactive title so there are processes legal and technical for dealing with this kind of thing. There is scope for MODs to cause trouble (e.g. spyware) without even being categorised as viruses at all.