I was at a seminar the other day with some librarians, on the resources that are available from the library, and how we can encourage our students to make better use of them. It's easy to forget that not everyone has developed skill for evaluating the quality and reliability of sources.
There seems to be some disagreement among librarians about the value and role of general search engines like Google (especially compared to subscription-based databases). Whereas among computer scientists below a certain age (in which, on most days, I'd include myself), you're more likely to find the sentiment that “If it's not in Google, it's not worth knowing.”
Anyway, at some point Wikipedia was inserted into the conversation. Again, librarians seemed to disagree on its value and role, but this time the emotion level really rose. One participant in particular took virulent offense that it was even mentioned. “People write any kind of shit on Wikipedia; that's just the wild west.” He insulted the no-lifes that contribute to Wikipedia, and basically said that the world would be a better place if it didn't exist at all.
It's rare to hear that kind of venom among peers in my field. I naturally made the mental connection to free software. It seems literally impossible for some people to believe that a loose-knit network of volunteers can, in their spare time, create operating systems, web servers, email clients, and the like. And to suggest that their efforts routinely surpass those of ‘professionals’ at corporations is offensive and un-American.
Many people strongly believe that nothing of value can arise from chaos, from anarchy. There is, I'm sure, some analogy here to evolution, too. The free software model is not precisely the same as Wikipedia, of course. Most projects would be insane to have their code repository writeable by just anyone. Among my peers, criticism of Wikipedia targets these more narrow, procedural decisions, because we know that, on the whole, the free software model works.
One librarian was more level-headed; she demonstrates to students what Wikipedia is all about by editing it in front of them: “Elvis Presley is alive and well, and living in Peoria.” She doesn't go as far as submitting the untruths and thus vandalizing the page, but it does emphasize – effectively, I think – that we need to treat everything written there with skepticism and check the sources.