It’s important to remember that fair use is media neutral and must be applied to any copyrighted material that you wish to use. Some forms of multimedia can only be used in their entirety (e.g., photos or images), however, permission must be obtained unless explicitly granted by the copyright holder. See the Digital Millennium Copyright Act.
Assume that most materials on the Internet are copyrighted, including emails. Once an expression is in a tangible medium, including a computer file, it is protected.
When creating and posting a podcast, all traditional copyright laws apply and should be followed. If use of the podcast is restricted to students in a class, fair use policies apply.
If creating a podcast with all original materials, the creator owns the copyright.
Commercial software is the most common form of copyrighted software. Conditions and restrictions of purchase will vary. If creation of back-up copies is permitted, make no more than one copy. Do not make copies of software documentation.
Shareware is copyrighted. In general, shareware allows users to make and distribute copies. After initial evaluation, users generally must purchase the shareware in order to be used.
Freeware is copyrighted. In general, freeware software stipulates that copies may be made for not-for-profit distribution. Freeware can generally be redistributed but not modified.
Open source software's source code is copyrighted by one or more persons/entities and distributed under an open-source license such as the GNU General Public License or Berkeley Software Distribution.
Public domain software is not copyrighted, and can be freely modified, copied, and distributed. The copyright holder must explicitly relinquish all rights to the software and must mark the product as public domain.