Linko90: As for DRM-movies, there's a bunch in the public domain like Night of the Living Dead.
john_hatcher: I think it depends on the country you are living in. It can be public domain in the USA, but not in an european country. If I'm wrong, someone might correct me.
Can't comment on the mentioned movie, but otherwise you are correct. The length and other conditions of copyright vary from country to country.
You can see this if you try to download "The Case-Book of Sherlock Holmes", which is possible in some countries and not possible in others.
http://en.wikipedia.org/wiki/The_Case-Book_of_Sherlock_Holmes#Copyright_history_and_challenges "The copyrights for Doyle's Sherlock Holmes stories expired in 1980 in Canada and in 2000 in the United Kingdom. In the United States, the only Sherlock Holmes works by Doyle still protected by copyrights are ten of the twelve short stories from The Case Book. The first two stories ("The Adventure of the Mazarin Stone", 1921, and "The Problem of Thor Bridge", 1922) are already in the public domain since they were published before 1923. The other stories will enter the public domain on 1 January of the year after the 95th anniversary of each story's publication: 1 January 2019 for "The Adventure of the Creeping Man"; 1 January 2020 for "The Adventure of the Sussex Vampire", "The Adventure of the Three Garridebs" and "The Adventure of the Illustrious Client"; 1 January 2022 for "The Adventure of the Three Gables", "The Adventure of the Blanched Soldier", "The Adventure of the Lion's Mane" and "The Adventure of the Retired Colourman"; 1 January 2023 for "The Adventure of the Veiled Lodger" and "The Adventure of Shoscombe Old Place"."
As far as movies go, the source material itself may become public domain, but restorations and corrections by some party may have their own protections.
Still remaining in the Sherlock Holmes topic, some Basil Rathbone movies are available as public domain versions. However, the versions restored by UCLA Film & Television Archive are not public domain.
So anyone who wants to get the best version available has to buy a physical format to view them.