If in doubt, it is recommended that users ask permission. He contends that copyrights should be assumed unless an author makes an unambiguous statement or overt act that indicates intent to dedicate the work to the public domain. In other words, simply posting a work on a computer network does not imply that the author has abandoned copyright. Many publishers and universities have policy statements, but they are little more than educated guesses as not much has been tried in court. Most of these policies have not dealt with the issues of materials downloaded from the Internet.
Judicial tendencies reveal that the more commercially viable a piece, the more it is protected.
Unpublished works are more protected than published, while artistic and literary expression is more protected. Factual reporting is less protected, and educational uses are less likely to be prosecuted unless they collide with the commercial issue. There have not been many court cases to test the legality of using the electronic documents and communications of another person or company. With the existence of e-mail, it is very easy to ask for permission. Permissions for all 9 illustrations requiring it in this article were granted within 12 hours of having asked for them.