I knew that Wikipedia was going offline today to protest the Stop Online Piracy Act, but I did, absentmindedly, click on a link to it once, I can't remember what for. I found what I needed elsewhere.
What I would have missed is Google. I can't remember when I last used another search engine. What would I have used instead, Bing? Yahoo? Remember AltaVista, MetaCrawler, Lycos?
Our public-access users are offered Bing by default in the Internet Explorer search box. I sometimes have to help them choose the authentic link among the commercial results of their searches. A search for where to apply for "food stamps" may steer them into confusion if they don't know how to distinguish the state agency link from the others.
Google also places commercial links at the top of search results, but not as much as Bing. We have an open-source operating system, (Linux), and an open-source encyclopedia, (Wikipedia), but there is not yet an open-source alternative to Google. And perhaps that is to the credit of Google, which is about as public-spirited a corporation as you could hope for.