The Heartland institute folks have now formally responded to the released documents. Here’s the most important paragraph:

1. The Fake Memo document is just that: fake. It was not written by anyone associated with Heartland. It does not express Heartland’s goals, plans, or tactics. It contains several obvious and gross misstatements of fact. Publication of this falsified document is improper and unlawful.

Heartland Institute is now asserting formally and legally that the particular memo is a fraud. DeSmogBlog and others continue to assert it’s not a fake. If they’re wrong, it could be fairly expensive.