Several extensions of the "alt.*" hierarchy have become quite successful on their own. A number of newsgroups have taken advantage of the freedom of the "alt.*" hierarchy to create a number of newsgroups that specialize on certain topics, as opposed to the broader "generic" discussions of the Big Seven hierarchy. For instance, the "rec.*" hierarchy may be home to the movie discussion newsgroups "rec.arts.movies.current-films", "rec.arts.movies.past-films", and "rec.arts.movies.reviews"; but the "alt.movies.*" hierarchy contains more focused discussion groups including "alt.movies.silent", "alt.movies.hitchcock", "alt.movies.kubrick", and "alt.movies.visual-effects".