I see nothing wrong with that as an avatar.
This is an international board. There are plenty of countries where topless sunbathing, male and female, are commonplace.
There is plenty of art where topless women form the main subject of the composition.
If I were to chose this as an avatar, would it be offensive
http://www.windows.ucar.edu/mytholog...us_milo_sm.jpg
(shrunken to the proper size of course).
We have burned enough books today, in my opinion a topless picture is not offensive. Let us not become censors for the sake of it.