Are you SURE you don't have any of these? That's one of the interesting things I've learned over the years. You may THINK you don't have any, or that you have never gone out of your way to get such. But that presumes that when you visited YouTube that the unlicensed excerpt you watched wasn't cached on your computer, and won't be found and used as evidence against you. That a friend or family member never borrowed your computer for a couple minutes to check email and left a copy of an attachment they shouldn't have had. And so on...

Oh, and you think folks who have no problem casually planting a bag of something in your car would have a problem dropping some files on your computer if they think that would help?

I'm not being contrary either, but to claim that you have nothing to hide could be seen as perjury for someone who wants to make sure they get you of something. And in this day and age I suspect the odds that you have something is higher than you may believe.