TERF stands for “trans exclusionary radical feminist” and they are a group that basically believe trans people existing threatens feminism and women in general. #TERFs

They have an obsession with protecting womanhood and women that ends up... actually policing womanhood and women.

TERF logic unfortunately spirals down into objectification and an obsession with policing women’s bodies and sex organs. Which is, ironically, exactly what feminism is supposed to oppose.

When you start to try to decide who gets to stay in the club of “women” and who doesn’t, things get sticky quickly. For instance, if binary trans people are excluded, why? Do trans women who are socially perceived as women (who “pass”), count? And if not, how will you tell?

Do trans women who have had genital surgery, and are literally indistinguishable from cis women, not count? Why not? What makes them any different than people born intersex who align themselves with womanhood?

“It’s about chromosomes!!” TERFs will say, but those aren’t clear cut either. XX and XY aren’t the only options. What about people with genetic disorders with multiple sets of chromosomes? What about women like Castor Semenya, who has given birth, but has XXY chromosomes?

If you define it by ability to reproduce, you exclude all infertile women (do you stop being a woman when you hit menopause?) and include many fully-passing binary trans men. If you define it by breast tissue, you exclude anyone who has had a mastectomy. This goes on and on.

The point is: biological essentialism doesn’t work, because biology is not nearly so essential, simplistic or clear-cut as #TERFs make it out to be.