The series ended abruptly with no closure. Through fan support Serenity the movie was spawned to bring closure. It did poorly in the box office with $38 million in ticket sales not clearing the $39 million production budget. Why?! DVD sales helped. The fans begged for more. Whedon has declared Firefly over. Now Universal sues to fan to stop promoting Firefly/Serenity. So, now the fans are billing Universal for time spent promoting the movie.
See also and also. Expect a take down notice on this so if you like it download it with keepvid. Of course, there is a wikipedia entry.