For those of you who missed the story, you can read all about Rob Granito in this article.
The short version is that he was selling other people's work at comic conventions and passing them off as his own creations.
Naturally, this caused Lee much agitation. But rather than sit back and do nothing about it, he put marker to paper and created this comic.
Needless to say, I think Rob Granito will now think twice about such shady dealings...