Science denial is a dangerous trend. There have always been people who won't accept the evidence at hand but choose to cling to their dear beliefs. They can't be persuaded by any amount of evidence presented to them or by disproving their unfounded beliefs. Well, that's fine, let them cling to their beliefs if it makes them feel better.
But that's not what's worrying me. What's worrying me is when otherwise normal and smart people start abandoning reason in favor of all kinds of fads and hype. There are a number of examples from recent years. Valkee [1], the Ear Light is one from right here in Finland. Another one is the magnetic therapy bracelets that even a lot of famous athletes got into promoting for big bucks. But these things are harmless. If you want to spend your money on these kinds of fads, you are welcome to.
But when your misguided beliefs start affecting other people and their well-being, that's when I take offense. One of the most alarming examples is the vaccine-denialism rising in the US. Parents are refusing to get their children vaccinated in fear of conspiracies that purport that they actually make your children sick to sell more medicine. That's just proposterous. Thanks to vaccinations, we have wiped some nasty diseases from the face of the planet like Polio.
There's a great TED-talk on the subject by Michael Specter, go and check it out [2].
Valkee, http://www2.valkee.com/uk/
Michael Specter: "The Danger of Science Denial" at TED
Science denial - A guide for scientists by Joshua Rosenau
