Attorneys specializing in entertainment law and copyright infringement are often consulted by authors and publishers in the event of book copyright infringement. The rise of the world wide web has led to an increase in copyright infringement, and web users regularly copy works online that violate the rights of a copyright holder. Entertainment or copyright lawyers may be employed to guard against book copyright infringement, sending cease and desist letters when necessary to infringers, and pursuing further legal action when necessary to remedy a copyright infringement issue. Often publishing houses own the copyright to the works they publish, and these companies have more resources with which to pursue copyright infringement claims. In other cases, individual authors may hold the copyright to their books, and may independently hire an attorney to resolve infringement issues both online and in the real world. Copying a book or extensively quoting from a book without proper attribution generally is considered a copyright infringement, unless fair use laws apply.