The 22-year-old proudly flaunted her assets by going naked from the waist upwards as she did a spot of shopping in Manhattan on 27 May, posting two images of her outing on Twitter.
Scout labelled one photo: "What @instagram won't let you see #FreeTheNipple." Another had the caption: "Legal in NYC but not on @instagram."
Addressing any critics, she added: "My comfort with my body should not be dictated by how others perceive me. However, I don't wish to force this view on anyone. If you don't like what you see, simply unfollow me."
Scout was angry at an Instagram policy of deleting images showing nipples. Her Instagram account was deactivated after such a photo was posted - but she managed to change her profile name to Scout (Areola) Willis before that happened.
It follows the deletion of Rihanna's hugely-followed Instagram, which was taken down after she uploaded pictures from her nude Lui magazine shoot.
My comfort with my body should not be dictated by how others perceive me. However, I don't wish to force this view on anyone.— Scout LaRue Willis (@Scout_Willis) May 27, 2014
Since Scout's stunt, which has attracted headlines over the world, Instagram has released a statement to E! News.
"We try hard to find a good balance between allowing people to express themselves creatively and keeping Instagram a fun and safe place. Our guidelines put limitations on nudity and mature content. Once content is reported to us, we review it and remove if it violates our policies."
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