Huh? It doesn't matter that it's been used in DVD-9...
If DVD9 uses the same alloy and was in existence before this patent was filed
That is, DVD9 came out last millenium. If when it came out last millenium it used this silver alloy, Target's patent of this alloy in 2004 is invalid, because the tech was already in use - prior art. If DVDs used a different reflective compound, and the silver alloy was developed by Target after DVD9's release, filed for patent in March 2004, and only after then used on DVDs, then the patent isn't invalidated.
It all depends on the date things happened, and no-one yet saying the same alloy is used on DVD9s (if it is - no references have been given) has said when it came into use. As is the norm for these patent threads, there's lots of important little facts that are being overlooked when people attribute blame. Some people aren't waiting to get all the info, despite me trying to present alternative cases to show that without the facts, we don't know which one of several possible situations exists. This thread is a text-book showcase of the usual 'trial by media' response. C'est la vie.