sales attributed to personal use of word processing or accounting software is not negligible.94
When factoring in software that is almost exclusively for personal use like music or video games,
it is likely that the Japanese copyright law fails to protect a significant portion of copyrighted
software against unauthorized use. Also, by defining infringement for unauthorized use such that
the software must actually be used in the conducting business, the Japanese legislature has not
only neglected to protect a large portion of the software protection, it has also limited
infringement to the functional use of software. This requirement to prove that the software was
not only accessed without authorization but used in the conducting of business presents a
potentially daunting task for copyright holders who cannot trace the software to a violation of
another exclusive right.