“There was a cloud over the mouse ...”

You don't often hear someone say “There was a cloud over the mouse,” but that phrase came naturally at the recent (May) Princeton Microsoft Intellectual Property conference. At the patent session, where much of the audience expected to hear about Blackberry or other trolling patents, one panelist got up and apologized, “I'm sorry, but I'm going to talk about mice.”
“(Mice? Did he say he's going to talk about mice?)” said a small voice behind me.
And the panelist launched into a talk about how easy it used to be to get specially genetically bred mice for experiments. You just called the lab that grew them, and they sent you some.
But today, some of these mice, or their special genetics, are patented, and access to them is restricted, often by onerous licensing agreements that create “clouds over the mice.”