You should visit Wikipedia Watch because they examine the consequences of its massive influence on what passes for reliable information:
“While Wikipedia itself does not run ads, they are the most-scraped site on the web. Scrapers need any content in order to carry ads from Google and other advertisers. This entire effect is turning Wikipedia into a generator of spam. It is primarily Google’s fault, since Wikipedia might find it difficult to address the issue of scraping even if they wanted to.