Ilovecheese
It's not really transwemen that are the danger to women, it is men pretending to be transwomen. Which they will if self identifying becomes law.
I agree with this, and with vegansrock's comment about men's voices being louder than women's.
I think it is a nonsense to say that you wouldn't necessarily be safer with a woman than a man (and to suggest that gay women shouldn't use female toilets is just idiotic). Most men are, on the whole, significantly stronger than most women, and biological men are far more likely to commit crimes of a violent or sexual nature than women. Gay women are biologically female and pose no more of a 'danger' (danger of what?) than straight women.
As Mollygo says, this topic has been discussed many times before, and it is a matter of time before we get lectures on waves of feminism, accusations of being stuck in the 70s and reminded that we don't know what is under anyone's clothes and that transpeople have been around for ages.
All of that is true, but until now transwomen haven't been legally able to access female spaces, and until now we were all agreed on what being 'female' actually means. Gender and sex are different - gender is a social construct (ie we teach and learn what is appropriate male and female behaviour), but sex is a biological fact.
Being able to claim to cross sex means far more than someone using the wrong facilities. It means that research into sex-based inequalities is rendered useless. Read Invisible Women by Caroline Criado to see how many things use the male as default - from the size of iPhones to crash test dummies. If men define as women that sort of thing will never improve, and nor will government policies about things like gender pay gaps or pensions. Men can identify as women and insist on being housed in female prisons, or join female groups and access changing rooms and swimming sessions designed for women-only access.
It is a minefield. Many people (myself included) are supportive of those who are seeking to live as women and have gender dysphoria, but not of the right to self-identify and be granted automatic access to women's rights and spaces, whereas TRAs (trans rights activists) insist on No Debate, and call anyone who questions their insistence that 'women' means 'anyone who says they are such' is transphobic and must be opposed at all costs.


