I'm Elise Hu. This is TED Talks Daily. What is the most important item you have on you each day? The one that you would feel lost without, the one that contains the most data about you? Your phone, right? In today's archive talk from TED Women 2019, digital security expert Eva Galperin uses our attachment to our phones and the troves of information they contain as a reminder that they can also expose us to all kinds of danger when they're in the wrong hands.

I want you to travel back in time with me to the before time to 2017.

I don't know if you can remember it.

Dinosaurs were roaming the earth.

I was a security researcher.

I had spent about five or six years doing research on the ways in which APTs, which is short

for advanced persistent threats, which stands for nation-state actors, spy on journalists and

activists and lawyers and scientists and just generally people who speak truth to power.

And I'd been doing this for a while

when I discovered that one of my fellow researchers

with whom I had been doing this all this time

was allegedly a serial rapist.

So the first thing that I did was I read a bunch of articles about this,

and in January of 2018, I read an article with some of his alleged victims.

And one of the things that really struck me about this article

is how scared they were. They were really frightened. They had, you know, tape over the cameras

on their phones and on their laptops. And what they were worried about was that he was a hacker,

and he was going to hack into their hacker, and he was going to hack

into their stuff, and he was going to ruin their lives. And this had kept them silent for a really

long time. So I was furious, and I didn't want anyone to ever feel that way again. So I did,

what I usually do when I'm angry, I tweeted.

And the thing that I tweeted was that if you are a woman who has been sexually abused by a hacker,

...