It's generally not a good thing to be biased. Sure, you can have your opinions, you can even cling to them strongly, but if they start actually altering your perception of reality, things can get messy. Lucky for you, hard-to-read fonts are here to the rescue, and might be able to save you from opinionated ranting.
According to a study by the Journal of Experimental Social Psychology, making facts more difficult to read can severly undercut personal biases. In the study, Individuals with known biases were presented arguments for or against the death penalty. Those who got the easier version came out all the more polarized in their opinions. Those with the hard-to-read text were more metered.
In another experiment, subjects were shown a summary of evidence either praising or condemning the subject of a mock trial before being shown the actual dubious evidence itself. Subjects who read the summary in hard-to-read text tended to be more skeptical and moderate, where those with the easy text tended to roll with whatever bias they were handed.
While it's certainly a pain to run across a difficult font, whether it be one that's miscolored and low on contrast, or just an ugly one, it seems that forcing people to actually exert effort into reading things also forces them to give it some actual thought. The downside of course, is that that's also sort of a pain in the ass. Now if you'll excuse me, I'm off to go write a contentious essay on iPhone vs. Android in light grey Zapfino. [Science Daily]