美国的产权法的基本出发点就是让新知识在大众间最为广泛地得到推广和运用

The main goals of copyright are to encourage the development of culture, science and innovation, while providing a financial benefit to copyright holders for their works, and to facilitate access to knowledge and entertainment for the public. 

Copyright 的目的不是限制我们用。其实很多东西是不受copyright保护的。Copyright 的目的是给原作者一定的利润作为劳动所得。Copyright其实推广了很多东西的应用。