Come to think of it, a terabyte is a lot of data still (as is a gigabyte). Just not for movies these days though.
Most torrents at 720p (and seemingly fine quality to me) come in around a GB. So it's enough for almost 1000 movies.
Good quality 720p should definitely be more than a gig for movies. Even high quality 480p rips came in at over a gig for most movies. I'm sure the torrents are watchable, but there are sacrifices being made somewhere.