Is everything on the Internet in public domain, and therefore fair game?
A work enters the public domain only after copyright expires, or if the creator has designated the work as such.
Most material found on the Internet is protected just like any other material (unless otherwise indicated). Text, charts, graphs, tables, photographs, music, movies, graphics, postings to news groups, blogs, e-mail messages, images, video clips, and computer software do not lose copyright protection simply because it is posted on the Internet.
However, new legislation allows educators to copy, distribute, communicate, or perform, works found on the Internet, provided that:
1. The work is properly cited (e.g. source, author, performer, maker, and/or broadcaster)
2. The work is publicly available (e.g. access is not restricted or password-protected)
3. There is no clearly visible notice (not just the copyright symbol alone) prohibiting the intended use
4. It is apparent that the work was made available with permission from the copyright owner.