Instagram is under fire for what critics call a sexist community guideline over a nipple showing.

Women from all over are posting photos of themselves topless on the photography platform but with one major detail added- instead of showing their own nipples, they sport a cut-out male nipple. What is the visual difference between male and female nipples? Nothing, besides the gender they’re on.

“We know that there are times when people might want to share nude images that are artistic or creative in nature, but for a variety of reasons, we don’t allow nudity on Instagram,” the app says in its community guidelines, “This includes photos, videos, and some digitally-created content that show sexual intercourse, genitals, and close-ups of fully-nude buttocks. It also includes some photos of female nipples, but photos of post-mastectomy scarring and women actively breastfeeding are allowed. Nudity in photos of paintings and sculptures is OK, too.”

The person behind this project is artist Micol Hebron who created the template of a male nipple in order to make a statement about online censorship rules in regards to women’s bodies. The Free The Nipple campaign is in protest to Instagram’s rules and demonstrates the pointlessness in differentiating between male and female bodies.