There are lots of legal options, such as The Internet Archive, where you'll find an extensive collection of music, software, TV shows, movies, books and more, all available free and legally.
For this tutorial, we're going to see what Charlie Chaplin movies are available from the Charlie Chaplin Festival collection.
Hear the word 'torrent' and you probably think of piracy, but the technology can be used perfectly legally to share open source, public domain and copyright-free movies, software, books, music, podcasts and much more.
It's also gaining traction as a legitimate way for artists to distribute their work; companies including Blizzard Entertainment and CCP Games have chosen to use torrents to distribute content legally.
As well as using torrent files as described above, you'll also encounter magnet links.