However, there is no clear cut acid test to determine what is or is not fair use. These factors are not equally weighted, with the fourth factor often taking precedence in most copyright disputes. Only courts of law can settle cases of fair use disputes. In most disputed uses copyright holders will ask fair users to cease their use of materials without resorting to court remedies. Fair users are most commonly thought of as educators or students, but home consumers are also fair users.
Fair use gets even more complicated when international law is considered.
Not every nation adheres to the U.S. legal definition of fair use and with the Internet being such a nebulous jurisdiction there will be increased interest by commercial entities in the near future concerning fair use matters.