Restores your faith in people.
kuro5hin.org has an article about: "The case of Wikipedia, a free online encyclopedia of over one million articles where anyone is able to write or edit any article at any time. According to the canon of academic orthodoxy, Wikipedia has no right to be as well written, professional, and accurate as it is. Not to say it is perfect, it isn't, but the vast majority of the articles are well written and many are comparable or better than their encyclopedia Britannica equivalents. This from a website where any person can write or change any article at any time, with no one paid to do quality control and no real punishments to those who vandalize the system other than being banned from the site itself. How then was Wikipedia able to accomplish this, despite all the naysayers?"
You may notice I often link to to the Wiki when posting because of the wonderful articles on it. So why does it work. I think it is because basically people are good, helpful and trustworthy. If you believe that then you are one of us. If you believe no one can be trusted than you believe in regulation, legislation and persecution. The Wikipedia is a shining example in a dark and depressing world.