If they have sufficient evidence that both the existence of kiddie porn on the drives, and the defendant's ownership and control over those drives, are "foregone conclusions" (which is the standard that needs to be met to avoid 5th amendment protection), why isn't he simply charged on the basis of that evidence?

Includes the exact quote from the judge:

"Let me say what I think your problem is. You can use these harsh terms, but you are dealing with something new, and the question is, does the statutory monopoly that Congress has given you reach out to that something new. And that's a very debatable question. You don't solve it by calling it 'theft.' You have to show why this court should extend a statutory monopoly to cover the new thing. That's your problem. Address that if you would. And curtail the use of abusive language."