It amazes me how hyped up oink is. I'm considering giving away my account (haha just kidding i love oink).
Caliboy: Sweet. I work in IT too. It sucks. I don't get what you mean when you say the Mac addy you had 6 months ago. A mac addy is static and once they have it, they have it. HOWEVER, I do think you're correct in what you're saying. Proving you actually have the stuff they claim you downloaded is very difficult. They will have to raid the location of the said stuff and secure it from the corresponding MAC addy that's in question. Then, they can't get you for downloading the said stuff. HOWEVER, they can get you for any number of other things including and not limited to intent to pirate, all the other shit you have laying around that's pirated, etc etc etc. They will not be able to get you for "downloading on limewire" or "torrenting" unless they have the hypothetical computer and the downloaded copies.
Thus, to avoid getting busted, burn and delete your stuff. Or don't download shit.