If you are a woman who does not like sharing your bathroom with men who claim they are women....

then you probably want to stay away from NYC. From an article in the NY Times (might not be available for viewing without membership by the time you click),

The Metropolitan Transportation Authority also agreed last month to let people define their own gender when deciding whether to use the men's or women's bathrooms.

Apparently NYC has taken it upon itself to re decide gender. Some more "thought provoking quotes" from the article.

Joann Prinzivalli, 52, a lawyer for the New York Transgender Rights Organization, a man who has lived as a woman since 2000, without surgery, said the changes amount to progress, a move away from American culture's misguided fixation on genitals as the basis for one's gender identity.

“Its based on an arbitrary distinction that says there are two and only two sexes,” she said. “In reality the diversity of nature is such that there are more than just two, and people who seem to belong to one of the designated sexes may really belong to the other.”

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But some psychiatrists said that eliminating identification difficulties for some transgender people also opened the door to unwelcome advances from imposters.

“I’ve already heard of a ‘transgendered’ man who claimed at work to be ‘a woman in a man’s body but a lesbian’ and who had to be expelled from the ladies’ restroom because he was propositioning women there,” Dr. Paul McHugh, a member of the President’s Council of Bioethics and chairman of the psychiatry department at Johns Hopkins University, wrote in an e-mail message on the subject. “He saw this as a great injustice in that his behavior was justified in his mind by the idea that the categories he claimed for himself were all ‘official’ and had legal rights attached to them.”

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So don't assume that she is a she or he is a he just based on their prominent anatomical features. Especially if you are in NYC ;-)