[lemma=□]
[lemma="file-sharing"]
For two reasons , nonpermissive P2P file-sharing of copyrighted materials is extremely difficult to police . File-sharing software companies have been battered by a string of successful legal suits by the entertainment industry . YouTube has stirred memories of a Digital Rights Management frenzy that had copyright holders up in arms over the original Napster , which was once an illegal file-sharing service . Macintosh and Windows users should be sure they understand file-sharing options so they do n't mistakenly share private information with everyone on the Net . Those efforts have included filing lawsuits against individual students at other universities who were believed to use peer-to-peer file-sharing networks on university servers in violation of copyrights of musical artists .