I think how Facebook translated the site is one of the biggest examples of proper crowdsourcing. It does take some expertise - namely knowledge of two languages

I think how Facebook translated the site is one of the biggest examples of proper crowdsourcing. It does take some expertise - namely knowledge of two languages. But the set of people with that kind of knowledge is definitely big enough to call it a crowd. I'll have to ask internally at Facebook how many people were involved. My guess would be more than 1000.