A helpful way to illustrate the issues here is to look at the matter of conventions and laws regarding the use of other kinds of public resources, such as roadways and sidewalks.

Used to be, roads were for - and shared by - pedestrians, people on horseback and in vehicles drawn by horses or other animals such as mules, or drawn by humans as in the case of rickshaws. Then in the late 19th century bicycles were invented and started to become popular, so the people already in the roads had to budge up a bit to accommodate people on bikes. All good until the 20th century when the internal combustion engine was invented.

Very quickly the roads were filled with automobiles, motorized carriages and motor trucks, crowding out, outpacing and often terrifying the pedestrians, people on horseback and in animal- and human-drawn conveyances, and very often frightening the horses and other animals too. Soon sidewalks were invented, along with road lanes and a plethora of rules governing what kind of vehicles could use the road, who was allowed to drive them, limits on the speeds they were allowed to travel, requirements to use horns, horse blinders, and so on. Which became codified in traffic laws and led to innovations like driver's licenses, traffic signs/lights, traffic police, driving lessons/schools and tests, along with new bureaucracies like DMVs.

In my own lifetime, I've witnessed many conflicts arise over who and what kinds of vehicles get to use public roadways and sidewalks and under what conditions - and changes in the customs and laws around these shared resources have occurred as a a result. Every time a new mode of wheeled transport or recreation comes on the scene - roller skates, kids' bikes with training wheels, skateboards, Segways, razors, roller blades, golf carts, bulky motorized mobility scooters, oversized prams, double-wide strollers, space-hogging jogging strollers, food carts, 18 wheeler trucks, SUVs, super-sized SUVs like the Ford Expedition and Hummers, super-long party limos, super-compacts, mini cars, three-wheeled vehicles like tuk tuks and so on - there has been conflict and discussion about how to incorporate them into the flow of human traffic to be fair to them and to all others using the roadways and sidewalks. Similar conflicts have arisen over the use of paths in parks and nature trails that originally were meant for walkers, hikers, snowshoers, X-C skiers, dog-walkers and people pulling sleds - but over time were increasingly taken over by people on mountain, dirt and BMX-type bikes; snow mobiles; motorized ATVs, etc.

Other conflicts have arisen over the way skateboarders have shown a tendency to move in on, and take over, public places like parks, parking lots and public stairways, along with ramps and handrails meant for people with physical disabilities who use walkers and wheelchairs or need to rely on handrails for balance, strength and stability.

I think today with women's restrooms, change rooms and other female-only spaces we're at a similar juncture to the times in the past (and present) when new kinds of transport and recreational vehicles led to - and continue to cause - conflicts over roadways, sidewalks, foot paths, stairs and other kinds of public amenities meant for specific groups such as persons with mobility issues.

Women and girls who've used, and use, testosterone along with surgeries to remove their breasts and reshape their bodies (such as the internal abdominal prostheses that El Page has had implanted), and who also use penis packers, in order to change their appearance to resemble males and can (try to) "pass" as men or boys have created a predicament for themselves and for the vast majority of girls and women who do not taking testosterone and are not trying to create the pretense/impression that we are male rather than female. Women and girls who've chosen to change their appearance so radically that they look like men to others have to know that their presence in women's loos and other female spaces like locker rooms, change rooms, mat wards, hospital wards, rape refuges etc is bound to be distressing and frightening for many bog standard girls and women. And I've heard many so-called "trans men" acknowledge this.

I think this problem that is of "trans men's" making is also theirs to devise solutions for - solutions that suit not just their sister/fellow "trans men," but which take into account the feelings, needs and sensibilities of the rest of the female population. I don't think it's a problem that should be foisted onto "GC" people and portrayed as one we have an obligation to solve.

BTW, as the poster here who has had more years - nay, decades - using women's restrooms, locker rooms, change rooms, etc than most or all other posters, I can testify that historically the majority of girls and women in the country and region where I've spent most of my life - USA, NY metro area and New England - have not seemed to have had any problems with the presence in such spaces of girls and women who in today's nomenclature would be described as "gender nonconforming" or even "mannish" in appearance and affect. Butch-looking women and girls have always been around, as have women who don't at all conform to today's ridiculous ultra "feminine" dress and grooming standards. Back in the 70s, 80s and 90s, the bulk of women I used to see in loos and locker rooms, as well as in female spaces like breastfeeding support groups and "Mommy and Me" classes, would be considered "GNC" by today's standards. The big difference is that back then, there wasn't a flood of girls and women trying to give the impression that they were not female by taking T, growing and proudly sporting beards, getting their breasts removed and undergoing body-sculpting, wearing penis packers or getting phalloplasties.