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 they are posted on the Internet.
However, educators are allowed to copy, distribute, communicate, or perform, works found on the Internet to their students, provided that:
- The work is properly cited (e.g., source, author, performer, maker, and/or broadcaster),
- The work is publicly available (e.g., access is not restricted by a Technological Protection Measure),
- There is no clearly visible notice (not just the copyright symbol alone) prohibiting the intended use, and
- It is apparent that the work was not made available in violation of the copyright owner’s rights.