Paradoxically there are many people who are conditioned to believe the random blog over the newspaper. People have been told to "think for themselves" and "do their own research", and so when they stumble on a conspiracy-minded blog, it feels like a more authentic voice than mainstream media.
I don't know what the solution is. It's impossible and unreasonable to expect individual bloggers to hold the same standard as newspapers traditionally did. Maybe social networks could do something to educate readers?