#FreeTheNipple is currently trending on Twitter.
Now... I firmly believe that North America is has a stupid hang-up about sexuality which causes all kinds of societal problems; we are both overly sexualized and puritanical all at once. There is something wrong with a society that can show murder on primetime TV, but not breasts.
That said, something about this idea that a hashtag on Twitter is going to change anything is hilarious - I'm 99% certain that most people looking at the tag are doing it precisely in the same way I did: "Wait a sec, people are posting pictures of their boobs online? As a devout believer in boobs in general, I feel I should show my support and look." And no, that does not directly contradict my statement above.