Bill Poser at Language Log has looked at the FCC's ruling that ABC violated decency standards by briefly showing a woman's naked buttocks, and finds it wanting. In particular Poser critiques the FCC's claim that buttocks are a "sexual organ," legally or otherwise.
The buttocks are not used for sexual reproduction so they are not a sexual organ. Indeed, they are not an organ of any sort, which is defined by Wordnet as: "a fully differentiated structural and functional unit in an animal that is specialized for some particular function". Unlike the heart or the kidneys, the buttocks are not "specialized for some particular function". . . .
The problem for the FCC is that it wants to enforce a broad notion of indecency that includes display of the buttocks but that its own regulations contain a narrower definition. Both in its ruling generally and in its mis-citation of the case law in footnote 23, the FCC appears to believe that it can expand the definition of indecency from what it is to what it would like it to be by fiat.