Why are C-SPAN’s recordings copyrighted?

Carl Malamud wrote an interesting letter to C-SPAN’s Brian Lamb about use of C-SPAN congressional footage (local copy). Speaker of the House Nancy Pelosi posted a snippet of C-SPAN footage to her blog and C-SPAN cried copyright infringement. Sadly, Speaker Pelosi didn’t challenge this claim (even on fair use grounds, where she had a good [...]