IMDB provides plain text files user's can download and use which can be found here: IMDB Plain Text Files which is great but I don't see the ID used for each movie in any of the files.

Given IMDB specifically says not to use scrapers, data gatherers etc in their Conditions of Use how would one obtain the title ID http://www.imdb.com/title/tt1133985/ for each movie if they aren't included in any of the plain text files.

I've noticed there are some API's others have built that do include this ID so I'm wondering how did they manage to do that.