As a male, I wonder if a majority of women really would want to run around topless. I get no pleasure from having my breasts massaged during lovemaking, but it seems that a large segment of females do (personal research). So are female breasts not erogenous appendages? (as a man, I can only guess). Many females have feelings of inadequacy about their breasts just like many men feel about penis size. Breast enhancement is the number one cosmetic procedure performed in the U.S. with 307,000 performed in 2011. https://www.loveyourlook.com/breast/augmentation/articles.aspx?id=457 Why do women do this? To attract men, or to compete with other women? Why do married women do it? To satisfy their husbands, or to feel better about themselves? I don't think that you would find many men that would complain about a shift to equality in beach attire. Do women believe that it is men that are keeping them down in this regard? Sure for a short transition period in the U.S. men would have to reign in their natural reaction to staring or becoming aroused, but I think that period would be rather brief. Of course our current path towards Sharia law would take a detour.

We have a nude beach in New York at Robert Moses State Park and 99% of the patrons look like the two in the cartoon above.

I have given it much thought. I agree that it is "unjust" and silly to not allow women to be topless in public. But, why don't women run around the house topless? The next time you have company over, answer the door topless. Invite them in and ask them if they would like to remove their shirts (male and female). This is perfectly legal, yet I have never shown up at a friends house and seen his wife or daughters running around topless? Why is that? I live in a house with many females, and they don't run around topless even when I'm not around. Again, if you are going to start a movement, it has to start somewhere. Hell, we just legalized the recreational use of pot, anything is possible. Eventually it may become a blue law that is not enforced.
I have not been into a women's locker room at the gym, but do women generally walk around topless (other than showering)? Most men wrap a towel around their waist, but every once in a while you get "that guy."

On the other hand, I know plenty of guys who are generally uncomfortable being topless in public, except maybe at the beach.

I know there are several people here that suggest that the only reason that women don't go topless is because they wouldn't want to or other women would be "competing", and that men would like it/wouldn't care/ would get used to it. But there are a lot of cases where women are arrested/harassed/ fined for indecent exposure by breastfeeding their babies. Why is it then that having a breast out in public for necessity (it's the reason all mammals have breasts), and not for sex appeal or competition, still receives such negative and legal reactions, especially for an act that's been around as long as humans had been reproducing?