What is too explicit?

Found this article on daily mail about a student artists work not being displayed because of the explicit content saying it was offensive, loved the fact she stood up to the university about her work and paraded around in her underwear and show the university that sometimes art out there is shocking and controversial, and dismissed that it should be shown in a separate area or have only over 18's see the exhibit, the fact is with all that surrounds us in the modern day, explicit isn't so, explicit anymore  ! Should certainly have a warning, but not to show her work is abit harsh considering its contemporary art practice and its part of her srtudies for them and should be treated equally whatever the content!
http://www.dailymail.co.uk/news/article-2307926/Student-strips-exhibition-work-row-university-erotic-paintings.html

Thanks for reading
Annie