In order to use a work protected by copyright, permission from the author or compliance with fair use is required. The author can claim copyright infringement when these conditions are not followed, and this can result in legal penalties for the infringer.
There are government databases that give you access to the records in the US Copyright Office. Here are two:
Library of Congress and the US Copyright Office work in conjunction to create a searchable database for books. For books published after 1975, you can visit http://cocatalog.loc.gov. You enter an author or title and see the registration number and the year that the copyright was registered
Plagiarism is the use of someone’s words or ideas without giving credit. It can be avoided by properly citing the source material.
Copyright infringement is the unauthorized reproduction, distribution, display, etc. of a copyrighted work. It can be avoided by receiving permission from the author or by conforming to fair use guidelines.
Copyright infringement can result in civil and criminal penalties, including the following:
A more detailed summary can be found at The Future of Criminal Enforcement of Copyright