The problem with this license is that this phrase is simply there to be cute. There is no legal definition of Evil and I don't see how you can come up with one. It accomplishes nothing other than making the license incompatible with other licenses and adding uncertainty.
Comments
JSMin was removed from Google Code because of this licence. Douglas Crockford explains the reasoning behind the license: http://wonko.com/post/jsmin-isnt-welcome-on-google-code
Courtesy @llimllib:
The problem with this license is that this phrase is simply there to be cute. There is no legal definition of Evil and I don't see how you can come up with one. It accomplishes nothing other than making the license incompatible with other licenses and adding uncertainty.
They should probably ban themselves while they are at it...
Given their motto, shouldn't this particular clause be required rather than banned.