I put to Whittaker a case from Canada, where police officers shared racist and misogynistic messages in a Signal group which leaked only when one of them passed it on to the media.

A lawyer for one officer said the men believed Signal was as private and safe as their own home.

"If they had that conversation in the kitchen and their bro snitched, would it be: 'What are we doing about kitchens?'" she asks.

"It has to work for everyone or it works for no-one. This is the principle of fundamental rights. They apply even to assholes."

She points to a US woman jailed after Meta handed over messages showing she helped her daughter access abortion in a state where it had been criminalised.

Private communication, she says, protects people from many kinds of harm - "an abusive spouse, a misogynist law enforcement officer with access to a database, or an authoritarian government that doesn't think women should get educated".

What would she want to say to a woman who wants to enter the tech field but is intimidated by the gendered aspect of the profession?

"Do you love it?" she says.

"Do you sit down at a terminal and feel a rush of energy? Do you enjoy playing with and defining AI systems?"

Then she pauses and says: "Are you able to navigate interesting and gnarly environments where not everyone is going to be chill? Because there's nothing more dangerous than being a coward in front of a bully."

I ask her if these environments are full of bullies.

Her colleague says, "I think that's 2pm" - the time we agreed to end the interview.

Meredith smiles. "I'd say don't be a simp," she says, using a term for someone who shows extreme deference to authority figures.

"It's not going to help you. Don't laugh at the joke if you don't think it's funny."

Additional reporting by Katie Roberts