Our librarians strictly prohibit the use of Google searches and Wikipedia for research purposes. Our faculty are split, with puritans insisting on authorized sources only and libertines allowing free searches, Wikipedia, whatever in the research process. They all agree that you can't actually cite Wikipedia in your final draft, and that unauthorized sources are, at best, leads to ideas that can be shored up by good, old fashioned books published by respected authors.
No matter which side of the debate you take, you will be doing your students a disservice if you don't teach them how to use google and wikipedia because they will use them whether you forbid them or not. It's like the old argument against teaching sex education: if you don't teach students what sex is then it will never occur to them to try it.
One problem here is that we are mired in teaching facts and we want to know that the facts come from an authorized source. But education isn't a collection of accurate facts, and research is not the science of how to collect those facts.
Tech support people, engineers, and tech directors have benefitted tremendously from using free searches on Google. Got an error message? Just type it into Google. Worried that the answer isn't right? Just try it. If it works, it's right.
Ever wonder if you could take a picture of your iPhone screen? You can! Just type "take a picture of my iphone screen" into google. Then do what is suggests on the first search result. If it doesn't work, try the next search result. (You won't have to, though. The first one works.)
Or maybe you are curious about binary notation of numbers and you would like to know what two to the twenty-fourth power is in decimal notation. Again, use google. Type 2^24 in the search area and press return. Is it right? Try it in Excel. It's right.
Interested in the life of Alan Turing? There is a great biography of him in Wikipedia complete with dozens of authoritative references in an imposing bibliography. You can't cite the Wikipedia article in your research paper, but you can use those references and cite them.
I once attended a lecture given by a colleague about Ancient Greek pottery. She showed several beautiful images of famous pots. I asked her where she got the images and she told me she just did a quick google search for them. So I challenged her: "How do you know they are reliable." "Because I've seen the real things in the Metropolitan Museum of Art." This is a perfect example of the role of the teacher as validator.
Crowd-sourcing has overturned the old notion that crowds represent the lowest common denominator. Now you can throw a question, problem or project at the crowd and get the attention of the best and the brightest if you are lucky. New drugs have been discovered, chemical weapons identified, and traffic reports have become incredibly accurate thanks to the efforts of anonymous contributors to the common good. Sometimes there is a financial reward; sometimes it is just the satisfaction of being part of the solution.
Nothing can replace trained school librarians. They know which sources are age appropriate, accurate, unbiased and reliable. Our librarians are great at pulling together bibliographies for every occasion. But who will teach kids how to deal with the wild wild west of the Internet? We can either let them learn it on their own, or we can get them started in the right direction. But no matter what we do or don't do, they will be out there, searching, finding, and -- we hope -- validating their sources.
From Pre-K through 8th grade, our kids learn continuously about digital citizenship. It's part of our culture. We know they will have a digital footprint and we know that they will start building it very early. We don't know what technologies they will be using to build that footprint in ten years. So we teach the concept of the digital citizenship and bind it tightly to the values and morals of our community. We make our students resilient and adaptive, ready for the future, whatever it may bring.