What problem arise on disregarding copyright rules?

The copyright is the right of the creator of a book, film, cartoon or any work of art. Having the copyright means that the right to use the work of art rests with the person/the publisher/the institution in whose the copyright is registered. Violating the copyright rules would lead to facing a legal suit either by the person/publisher/institution. In some copyrights there is mentioned a particular period of time for which the person/publisher/institution can hold hold the right. However, if any individual is eager to use the work of art he can seek a formal, better a written permission from the ​person/publisher/institution for using the work as a reference.