Perhaps Keurig should print their logo onto the cups with said special ink, and the machine should identify the logo with an image matching algorithm. If I understand trademark law correctly, competitors wouldn't be able to reproduce the Keurig logo without the strong possibility of facing repercussions for trademark infringement. I mean in reality it wouldn't work well at all and just make consumers pissed, but I wonder what the legal situation would be if they could pull it off.