Here are the examples of copyrighted online materials from your list:
- An article from an Internet magazine - This is typically copyrighted material unless explicitly stated otherwise.
- Photos taken by a student on his blog - These are usually copyrighted by the student, unless he has given up his copyright.
- An illustration sold by an artist on her website - This is copyrighted material, as the artist retains rights over their creations.
The other items are generally not copyrighted:
- Lyrics for a song written in the 1800s - Works published before 1924 are typically in the public domain, so they are not copyrighted.
- A video game that is free for anyone to copy - If it is explicitly labeled as free to copy (like open-source games), it is not a copyrighted work.
- An excerpt from a novel published in 1913 - Like the song lyrics, this would also likely be in the public domain.
So, the correct examples of copyrighted materials are the article, the photos, and the illustration.