Fortune companies don't blog

"Just 6 percent of the Fortune 500 companies have one [blog], according to Socialtext's Fortune 500 Blogging Wiki.

Why is this? If blogging is still not widespread among companies, it is basically because they are afraid to lose control of their messages , they fear the transparency effect and are not altogether convinced of the legal limits of this medium."

http://www.iese.edu/en/files/6_34173.pdf