This clause was carried over to JSMin-PHP, a variation of JSMin by Ryan Grove. This software was hosted on Google Code until December 2009 when, due to the additional clause, Google determined that the license was not compliant with the definition of free and open source software, which does not permit any restriction on how software may be used.
JSMin-PHP was forced to migrate to a new hosting provider. According to the GNU project, the licence conflicts with Freedom 0 of the Free Software definition, and although "it may be unenforceable, we cannot presume that", therefore non-free.