If you've been using Instagram to post photos of your butt, it's time to stop. Today the social network updated its Community Guidelines with stronger language concerning harassment and more details on images with nudity. The "don't be rude" section of the guidelines has been completely revamped with more definitive rules that state, "it's never OK to encourage violence or attack anyone based on their race, ethnicity, national origin, sex, gender, gender identity, sexual orientation, religious affiliation, disabilities, or diseases." On the nudity front, bare buttocks, genitals, "some photos of female nipples" and intercourse are a no-go for posts, but images of breastfeeding and mastectomy scarring are allowed.Instagram also states that there are times when it will remove photos of partially or completely nude children from the service for safety reasons. It'll be interesting to see how comedienne Chelsea Handler pushes the limit on the "some photos of female nipples" guideline. She's has been posting images of her breasts and butt on the service in response to how Instagram treats male and female nipples differently.