A new California law will allow K-12 public-school students to use restrooms and join sports teams based not on their sex — but on their gender identity. That means that starting January 1, transgender students who are biologically male will be allowed into girls’ bathrooms and those who are biologically female will be welcome on football teams and in boys’ locker rooms.

So, naturally, some folks are freaking out.

Signed by Governor Brown in August, the School Success and Opportunity Act is the first of its kind in the U.S. But a group called Privacy for All Students has gathered thousands of signatures hoping to bring the issue to a public vote — and ultimately overturn the law. They say it’s unfair to regular guy-guys and girl-girls to have to share their facilities and, I don’t know, bonding zones with someone who has differently shaped private parts.

This particular fight centers around urinals and communal showers, but the transgender rights movement neither begins nor ends at plumbing. It’s happening on Dancing with the Stars, where Chaz Bono cha-cha-cha’d; and in the U.S. Army, where Wikileaks whistleblower Bradley Manning reinvented himself as Chelsea; and in the Girl Scouts, where a Colorado troop’s decision to allow a 7-year-old transgender child to join its ranks inspired a cookie boycott; and in the Miss Universe pageant, where a transgender Canadian contestant won the right to compete in 2012; and so on, and so on.

Let’s clear up some misconceptions before we go any further. Transgender people — the T of the LGBT community — are not necessarily gay, and they’re not simply “cross-dressers”; they’re people who truly feel as if they’re one gender, though their bodies bear the characteristics typical of another. They feel it as young children and as teens and adults. They are numerous, and they aren’t new to the world, but an increasingly tolerant society is making it safer for them to live as their authentic selves.

The concept is strange, though, for sure. It calls into question some of the few things in life we figured were absolutes and forces us to rethink our handy, trusted labels and admit we don’t really have everything all figured out. Still … there’s a difference between being uncomfortable with an idea — and being thoroughly undone by it.

Opponents of this new California law are expending actual human energy to protect the sanctity of public-school bathrooms — a place where nothing pleasant has transpired, ever. They’re not acting with reason, but reacting with fear. (Surprise: Leading the charge is the very same guy who spearheaded California’s gay-marriage-banning Proposition 8.) Don’t they realize gay students currently have every right in the world to use locker rooms with their same-sex classmates? Do they think a child would fake being transgender just for the opportunity to urinate next to the opposite sex? News flash: Girls’ bathrooms have stalls and, well, I never met a high school boy who had to be tricked into showing a girl his equipment.

I spoke to a former administrator at Dos Pueblos High School who made bathroom and locker-room accommodations for a student there who left after junior year as a boy — and returned senior year as a girl.

For the girl’s own safety, and to appease the parents of other students, they arranged for her to use less-frequented bathrooms and private showers. “It was a separate-but-equal solution, and that’s not right,” said the administrator, who regrets that the girl had to be treated differently than anyone else. But she’s proud to have helped the kid graduate as the person she’d always wanted to be — and to have paved the way for more students to do so.

“Separate but equal was the beginning of our civil rights,” she said. “And this is the beginning of our sexual rights.”