In relation to the classification of cultural works as intellectual property, the effort justification offers the more convincing defense. It is difficult to discuss the idea of intellectual property without considering the cultural context within which it operates. In the digital age, the concept of intellectual property can no longer be enforced by economic scarcity, thus it relies exclusively upon state intervention through the threat of legal consequences for copyright infringement. When a remix artist uses a sample from a film or song in the creation of a new work without permission, it is considered an infringement of the author's copyright in that work. Unlike commercial documentary films, remix videos are more likely to be issued with cease and desist letters and YouTube takedown notices than targeted for copyright infringement lawsuits. In history, copyright was assimilated under the catchall label of intellectual property rights, along with patents, trademarks, and a number of other contentious items, such as trade secrets.