Libraries facilitate access to information to the community in which they operate, offering products and services to the public, regardless of age, race, creed, gender or social status. In turn, librarians further the fundamental and inalienable mission to meet users’ information needs. While the right to access to information and the enjoyment of cultural property is guaranteed by international agreements, its exercise is affected by the law of copyright, generating tension of interests between rights holders and society. Copyright legislation affects many of the processes performed by libraries such as the services provided to the user, the conditions under which such access must be provided, and the role libraries can play in relation to conservation and preservation activities. This paper analyzes the laws of copyright in the United States of America, Spain, Chile and Argentina, in order to identify which library activities and processes are favored or restricted by such regulations. Finally, from this analysis, supporting evidence is given to substantiate the need to amend the Argentine legislation to incorporate those exceptions.