Dave Thomas points to an argument that is largely evidence-free but nevertheless alluring: Doug Kern at Tech Central Station on how the Internet killed off enthusiasm for UFOs:

The Internet processes all truth and falsehood in just this fashion. Wild rumors and dubious pieces of evidence are quick to circulate, but quickly debunked. The Internet gives liars and rumor mongers a colossal space in which to bamboozle dolts of every stripe — but it also provides a forum for wise men from all across the world to speak the truth. Over the long run, the truth tends to win. This fact is lost on critics of the blogosphere, who can only see the exaggerated claims and gossip. These critics often fail to notice that, on the ‘net, the truth follows closely behind the lies. A great many of us accept Internet rumors and hoaxes in exchange for fast access to the truth.