Freedom of Information Act, 9th exception.

There are 9 exceptions to FOIA. They mostly have to do with topics you would expect: national security, privacy, etc...

Then there is The 9th Exception (sounds like a title for a movie, right?):

"geological and geophysical information and data, including maps, concerning wells."

Of course the DOJ has some explanations. But to single out wells? Why would this information not be held under exception 1, or exception 4? Something (from a deep dark well) smells here. Thoughts?