I'll ask
again. What precisely are the privacy and security issues involved here? What are the threats and to what?
Can a file linked from a Matroska file be executed? (I can't imagine an argument in favor of this from a security perspective, but if that's the spec I'd be curious as to why it was designed that way.) What if the linked file has no executable privileges?
I'm not trying to beat a dead horse here, but all I see about this issue is some hand-waving about "security." What is the problem, and why can't it be easily addressed? And why is it seemingly a greater concern for *nix which overall has a tighter security model than vanilla Windows where most users run as root?
Edit: How does LoneShadow's patch address these concerns?