Another class of permissible restrictions on speech is based on intellectual property rights.[45] Things like copyrights or trademarks fall under this exception. The Supreme Court first held this in Harper & Row v. Nation Enterprises (1985), where copyright law was upheld against a First Amendment free speech challenge.[46] Also, broadcasting rights for shows are not an infringement of free speech rights.[47] The Court has upheld such restrictions as an incentive for artists in the 'speech marketplace'.[48]