When you visit the open course website, what you'll see is that a depth and a breadth of materials that's different from what you see on other campus websites.
With the CRU-email situation, the best evidence is that they were leaked through incompetence: evidence suggests that someone (probably a system administrator based on the file structure) left a giant file prepared for FOIA submission on an openwebsite, and it was snatched up and parceled out.