A couple of days ago, I noted my surprise that a person could be sued for copyright infringement by quoting even a single line of a song:<p><a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10672934" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10672934</a><p>How the heck can Richard Prince&#x27;s use of other people&#x27;s works be considered fair use if quoting a single line from a song is not considered fair use?