Furthermore, I only play emulators for which I own the original games. I'm uptight that way, so sue me.
Wishful thinking, but unless you dumped the games yourself from the original media and are never using that backup copy at the same time as the original, that doesn't make it any more legal than if you had just downloaded them without owning them. Whoever distributed them to you still committed copyright infringement on their own (since they were not authorized to make a copy and distribute it), and if you knew they weren't supposed to be sending you a copy but downloaded it anyway, that can leave you guilty of conspiracy and/or contributory infringement.

I'm not saying this is something you should not be allowed to do, but the thought that it is legal under current US laws is just a dream, so please wake up.