From time to time I've seen movies' or TV show episodes' scripts posted or quoted online - at first they were The Simpsons episodes, but Star Wars and Harry Potter films too, for example. There's even a question about sites in which to find scripts.
Are those scripts official?
I don't know if they are published by the directors/writers/producers, or if they are fan made. They seem too detailed to be fan made - and considered too much canon for just being the opinion of lots of nerds -, but I can't imagine why nor where do they publish them. What's the intention in publishing them?