Keith Olbermann, whose show “Countdown” will be reborn tonight on Al Gore’s progressive news station Current TV, addressed Netroots Nation on Thursday via video. Olbermann will deliver the keynote speech at Netroots 2012 in Providence, Rhode Island. “Countdown” was unceremoniously pulled off MSNBC, sending the unapologetic leftist commentator Olbermann to the West Coast. “The walls are closing in, not just on journalism, but on democracy. The walls, like anything else, are owned by huge corporations,” said Olbermann.