In the last century, movies used to be printed on film stock composed of celluloid that could combust in a flash and be gone forever. Today, it is rare for movies to be printed on film and transported manually to the local Roxy, Electric or Odeon. No catalyst was needed to destroy this method of film delivery. It simply took the introduction of the digital distribution employed for music, and increasingly books and movies. With cinereel distribution, if you lived outside London you would have to wait several weeks for the latest cinema release to reach your town. It's also the reason Hollywood movies could take months to reach the UK. Today, a movie can be distributed via hard-drives, optical disks or satellite and projected using digital projection systems instead of a conventional film projector.