It wasn't just a 'flip' decision to do this, when she caught up with them she did it again, making it really personal.  Then she said she was proud of it and would do it again.  Don't think she will have much of a case.  According to this story, the other guy took his stuff down and probably promised not to do it again which is what someone should do when they reflect poorly on their employer.  If the employer doesn't do something, it looks like they agree with the disgusting behavior.  Since she said she would do it again, its bye, bye and no recourse.  What did she think she would accomplish anyway?