The current study empirically demonstrates the widely discussed gap between copyright law and social norms. Theoretically founded in the sociology of law, the study uses a well-defined concept of norms to quantitatively measure changes in the strength of social norms before and after the implementation of legislation. The 'IPRED law' was implemented in Sweden on 1 April 2009, as a result of the EU IPR Enforcement Directive 2004/48/EC. It aims at enforcing copyright, as well as other IP rights, when they are violated, especially online. A survey was conducted three months before the IPRED law came into force, and it was repeated six months later. The approximately one thousand respondents between fifteen and twenty-five years-of-age showed, among other things, that although actual file-sharing behaviour had to some extent decreased in frequency, social norms remained unaffected by the law.