MEGAN THOMPSON, PBS NEWSHOUR WEEKEND ANCHOR: The special counsel investigating Russian meddling in last year's presidential election has obtained, through a search warrant, records of Russia-linked ads posted on Facebook, some by inauthentic profiles. That disclosure first reported by "The Wall Street Journal" and CNN this weekend follows a story published Thursday by "ProPublica" that revealed how Facebook advertisers could target ads specifically at anti-Semitic users.

Yesterday, NewsHour Weekend's Hari Sreenivasan spoke with one of the authors of that article, "ProPublica" reporter Julia Angwin.

HARI SREENIVASAN, PBS NEWSHOUR WEEKEND ANCHOR: Most people don't buy ads. How does ad buying work on Facebook?

JULIA ANGWIN, REPORTER, PROBUBLICA: So, the way it works is you go in and you say, I want to buy an ad and they offer you all sorts of options. You can do it by age, and by the city, and you can even do it by the zip code. You can type in some thoughts, like I want people who listen to Bon Jovi or I want people who are wearing nose rings, or whatever you were interested in, they will tell you how many people they think they have like that in their system.

SREENIVASAN: So, what did you guys do?

ANGWIN: Somebody gave us a tip that there was a category called Jew haters. So, we went in and we type "Jew hater" and there are like, cool, there's 2,200 of them you can target, and we thought, really? So, we bought an ad, because we thought maybe there would be an approval process like where it wouldn't go through, but then it went through. Then we thought maybe the bugs, so we bought another on, and it went through. And we thought maybe it was really — maybe that was crazy, so we bought a third one just to be sure which went through, and then we decided that they did have an ad category called Jew hater.

SREENIVASAN: You know, there is a screen that you have on your story, as you're doing this, you see all these other sort of almost suggested categories.

ANGWIN: Right. So, when you put in Jew space H, it suggests for you Jew hater, how to burn Jews, why Jews were in the world, and it suggested other things that were related. Their top suggestion was the Second Amendment which would be related.

SREENIVASAN: Are these phrases or categories that people have assigned to themselves or?

ANGWIN: Yes. It seems as though what happened here is these were described as fields of study and so, it seems as though people had put in their profile their field of study was these things. Everything you write in your profile where you fill out your interest, your movies, whatever, it just they just automatically turn it into an ad targeting category.

SREENIVASAN: Companies in the Silicon Valley often said, listen, it's not our job to censor. But that's not necessarily Facebook said when you confronted them with this.

ANGWIN: Yes. You know, they could have actually said, look, let and let live. But they actually didn't. They took it down. They took down the categories that we mentioned, but then they also took down all self-identified categories. They said, you know, we need to figure out how we can sift through these to make sure there isn't other stuff in here.

SREENIVASAN: So, how is this even fixable? I mean, there's no way that humans can sit there and look at every type of ad that every company across Facebook wants to buy.

ANGWIN: It's a big data problem for sure. But, you know, what's interesting, you think about the big data problems Facebook has solved defectively, automatic catching of every nipple, automatic photo-tagging of all your friends' faces, right? So, I feel like, I have faith if they tried, they could also figure out the big data algorithm solution to this one and just not sure that they had tried.

SREENIVASAN: Let's talk a little bit about the money at stake here. I mean, even if they shut the spigot off just for a few days or few weeks until they solve this problem, this is — this is serious money.

ANGWIN: Yes. I mean, Facebook, they have the most, you know, advertising dollars of anybody online. And that's because of this collection of all these teeny tiny micro-segments. And so, when you add up all their little micro-segments, it's going to be significant revenues, whether it's 1 percent or 2 percent of their revenues. It's still big numbers.

SREENIVASAN: Julia Angwin from "ProPublica", thanks so much you for joining us.

ANGWIN: It's great to be here.