When did trans activism really become a big thing?

The change to "woman being a feeling, not the female sex" self-id stuff - I became aware of it around 2016 so it must've started a few years before that.
This is a funny summary
https://janeclarejones.com/2018/11/13/the-annals-of-the-terf-wars/

Not sure when it became a big thing but I remember when I worked on a big campus style tech company around 1990 there was at least one male using the ladies toilet and he always left the loo seat up. No idea who as I never bumped into anyone in those loos - massive site almost no women on site so large ladies toilet with many stalls was always deserted, I remember it used to piss me off. Seat left up meant couldn’t avoid knowing a male had been in. I also remember being a bit confused as then I thought they wanted to blend in whereas leaving the seat up was a sign they weren’t female.

Working my way through Gender: A Wider Lens podcast and many interviewees mention 2014 as a big turning point in public sentiment on the issue.

I used to got to clubs in the 90s where you would see drag queens but there was no association at all with any unbrella other than they were all gay men. I worked with someone who claimed to have 'become a woman' in the mid 90s, but again, no hint of an umbrella or a movement or even any association with gay pride. People considered him as a gay man, as he lived with a man, nobody had ever heard of AGP. Similarly I last went to a pride event at about the same time and it was purely about lesbians and gay men. You'd see a few gay men in dog collars but there wasnt anything overtly sexual in public and no furries.

In my mind this all developed in conjunction with the internet and household access to it from the early 2000s. S
Unrestricted and easy access to weird porn and the rise of chat boards and groups where it was discussed and people were whipped up about it.

The non-binary, 72 billion sexualities, popularisation of trans identities as being 'normal' only happened circa 2012 and onwards.

'When' is an interesting question, but 'how' is even more interesting.

In Ireland, a group called TENI (Transgender Equality Network of Ireland) was set up in 2006 and swiftly became the only voice listened to by legislators, healthcare providers, etc. on the subject of gender, and became the recipient of large amounts of both state and 'charitable' funding.

'What does TENI think?' was what passed for scrutiny in dealing with sex/gender issues in Irish society from that time onwards. For example, the parliamentary 'debates' leading up to the Gender Recognition Act were more cheerleading than debates, with politicians of all parties specifically naming TENI as their only source of information about this thing called 'transgender'.

It is still the go-to group for gender-related quotes in the media, so when the Cass report was published, 'What does TENI think?' informed the press coverage.

Ireland provides an example of how much influence, funding and media dominance a small, focused trans rights group can quickly achieve, especially in a period of general social liberalisation.

Somewhere there's a post about a newsletter in the 1970s that brings them all together. Something about not allowing women to gatekeep what it is to be a woman. Does anyone know the post I mean?

ETA: in the trans umbrella thread.

Certainly, whatever course we take as transvestites, transsexuals and drag queens, we must first destroy the trap wherein regular women set up standards by which they accept or reject us
**
https://www.mumsnet.com/talk/womensrights/4281733-The-Trans-Umbrella-Is-Older-Than-You-Think?reply=108674196&

The GRA was passed in 2004, after many years of lobbying, most of it quiet.

Things ramped up since then, especially when Ruth Hunt took over at Stonewall and added 'T' to their remit, 2014.

As detailed in the opening chapters of The Women Who Wouldn't Wheesht, in Scotland at least, the real push to imbed gender ideology into Scottish civic life and institutions started from around 1997.

When the LGB rainbow flag started to mutate into the seizure inducing Rorschach test that it is today and Pride marches became a kink parade with kids as the audience.

When someone said “no”

https://www.mumsnet.com/talk/womens_rights/4938575-how-did-it-all-start

This one might help too

https://www.mumsnet.com/talk/womens_rights/4281733-The-Trans-Umbrella-Is-Older-Than-You-Think I think this could be relevant