A divided US federal appeals court says Chicago can enforce an ordinance banning women from baring their breasts in public.
By a 2-1 vote, the 7th US Circuit Court of Appeals in Chicago late on Wednesday rejected an appeal by a woman who was ticketed for exposing her breasts on national "Go Topless Day".
The dissenting judge objected to the majority's "premature" decision to endorse a law that she said might reflect "longstanding biases" toward how women should look in public.
Sonoko Tagami, a supporter of GoTopless Inc, a nonprofit advocating for a woman's right to go bare-chested in public, sued Chicago after being ordered to pay a $US100 fine plus $US40 in costs over a 2014 protest where she walked about with "opaque" body paint on her breasts.
Ms Tagami said Chicago violated her constitutional free speech and equal protection rights by letting men, but not women, bare their breasts.
Writing for the majority, Circuit Judge Diane Sykes said Chicago had an important interest in "promoting traditional moral norms and public order," and restricting exposure of "intimate, erogenous, and private" body parts.
"The list of intimate body parts is longer for women than men, but that's wholly attributable to the basic physiological differences between the sexes," wrote Ms Sykes.