Fair Use is a very grey area and this is on purpose. Here is a list of four criteria in determining Fair Use.
The easiest way to ensure you aren't breaking copyright is to simply get permission to use it.
If you are using it to comment, criticize, or parody the work, it falls under fair use.
Not Fair Use:
Remember that every country has it's own version of Fair Use. The version you should use is the version from the country of the works origin.
Things that do not make something Fair Use:
This law was added in 1998 by President Bill Clinton. It has a great deal to say about and to website owners.
Criminalizes the creation or production of technologies that circumvents technological protections.
Requirements for service providers to follow to be safe from prosecution for copyright infringement by their users.
This act allows for the making of copies of copyrighted material in the process of backing up data storage while making repairs or doing maintenance.
Provisions relating to various topics including: Exceptions for Ephemeral recordings, Distance Education, streaming sound recordings, and exceptions for libraries.
Yes, they included a copyright protection for the design and shape of boat hulls but only for boats that are under 200 feet in length.
Concerning works that have a copyright notice:
Concerning works without a copyright notice: