My, my, my. According to Little Green Footballs, left wing blogger Kos was paid by the Howard Dean campaign.

Any minute, I'm waiting for the torrents of abuse showered upon Armstrong Williams to begin falling on Kos.

What's so difficult about this for anyone to understand, left or right? If you're being paid by someone, just disclose it! It doesn't disqualify your opinions from being valid, necessarily -- it's just being honest with the people who read you, thereby honoring you with the gift of their time and their consideration.