Public Domain - Legally Available to Watch Online for Free Here...

This and many other films free of copyright etc. can be watched here: http://www.freemooviesonline.com/watch-free-movies/drama-movies/escape-from-sobibor.html

The reason this particular film is in the public domain is because it is NOT registered with the Library of Congress. This site has many other films, tv shows, series etc. that can be legally watched online for various reasons including pre-1923 films, films that were originally registered but never renewed etc.

There's some good stuff there, I found it when I was looking for this very film.

PS: Excellent film, I have been to Auschwitz Birkenau, have read countless books on the Holocaust (I recommend The Holocaust by Martin Gilbert or Auschwitz by Laurence Rees if you wish to learn more) and seen many films on the subject and I have to say this is one of the 'best' if that word is appropriate in this context.