Peak Zuck: "What's a shadow profile?"

Shadow Profiles is the industry term for the dossiers that Facebook compiles on billions of people, including people who don't have Facebook accounts, merging data from Facebook Like buttons and tracking pixels, outside data brokers, and data entered by Facebook users about their friends, including harvested address-books, tagged photos, and other personal information that can pertain to Facebook users and non-users alike.

Everybody who pays attention to Facebook knows about shadow profiles — except Mark Zuckerberg, who told Congressman Ben Lujan that he'd never heard of them.

Shadow profiles aren't just sketchy and creepy, they're also Exhibit A in the case against Zuck's justification for spying on us: "You agreed to this." Leaving aside the question of whether clicking past a EULA that no one has ever read is "agreement," there's no question that people who aren't Facebook users have agreed to let Facebook spy on them. They're not the only ones whose agreement was never sought before their privacy was invaded.

Zuckerberg: Congressman, in general we collect data on people who have not signed up for Facebook for security purposes to prevent the kind of scraping you were just referring to [reverse searches based on public info like phone numbers].

Lujan: So these are called shadow profiles, is that what they've been referred to by some?

Zuckerberg: Congressman, I'm not, I'm not familiar with that.

Lujan: I'll refer to them as shadow profiles for today's hearing. On average, how many data points does Facebook have on each Facebook user?

Zuckerberg: I do not know off the top of my head.

Lujan: Do you know how many points of data Facebook has on the average non-Facebook user?

Zuckerberg: Congressman, I do not know off the top of my head but I can have our team get back to you afterward.

Lujan: It's been admitted by Facebook that you do collect data points on non-[Facebook users]. My question is, can someone who does not have a Facebook account opt out of Facebook's involuntary data collection?

Zuckerberg: Anyone can turn off and opt out of any data collection for ads, whether they use our services or not, but in order to prevent people from scraping public information… we need to know when someone is repeatedly trying to access our services.