A woman definitely has the right to wear whatever she wants. At the same time you can't stop crazy people from being crazy. People are attracted to breast. A woman will draw the wrong attention when she has her breast out like that. It is silly to complain about harassment when you are purposely doing things that will garner negative attention.
Why is the attention negative? There's nothing wrong with compliments.
Most people (cultures) started out topless. Breasts are for babies. It shouldn't be a big deal.
There are 2 things it reasons why people fight for this.
1 Seeing breasts more often will lessen the

factor.
2. Seeing mornatural breasts will have a better effect on the self esteem of young girls. However, I think since they will be on display more, more girls will probably want boob jobs and nipple piercings.
But all in all. I don't think anyone is expecting everyone to walk around shirtless, just if it's hot or your at the beach, it should be no big deal.
Personally, I think the less clothes the better.