True, but I think the rational behind that is that imdb doesn't want someone creating a software that gets used by a lot of people which implements such a crawl

True, but I think the rational behind that is that imdb doesn't want someone creating a software that gets used by a lot of people which implements such a crawler. I doubt although I can't say for certain, that imdb much cares about someone who made a scraper to gather data for a one time aggregation like this. Of course, for a use case like OP has, the static data imdb offers would also have sufficed, I'd say. Of course, that data is not as "up to date" as the data you can scrape off of the web pages, but it would have been sufficiently "up to date" for such an analysis, I think.