Mark Zuckerberg testified for almost five hours Tuesday in a televised Senate hearing about Facebook’s privacy practices and data abuse. More than 40 senators had five minutes each to ask questions. Zuckerberg’s most frequent response? “My team will follow up with you.” House members will have their own chance to coax answers from the evasive Facebook CEO on Wednesday when he testifies before that chamber’s Energy and Commerce Committee.

It’s a rare opportunity. Zuckerberg has been heavily coached for the DC leg of his apology tour, but for the controlling CEO, with a cautiously curated personal brand, these hearings provide a forum to pin him down with facts and get his statements on the record.

The impetus for the hearing was the scandal over Cambridge Analytica, which collected data on 87 million Facebook users without their consent. But some of the most telling lines of inquiry on Tuesday focused on the longstanding tradeoffs from Facebook’s business model and the mechanics of data collection that Zuckerberg would prefer to obscure: How Facebook tracks you online and offline; what personal data you inadvertent reveal; how a $477 billion company that makes money from advertisers might still respect privacy.

There were few revelations, and a longer list of not-quite-answered questions. Some lawmakers had clearly been briefed by tech-savvy Facebook critics, but still couldn’t quite hit it home.

Toward the end of the hearing, Senator Kamala Harris (D-California) attempted to list the questions where she thought Zuckerberg had been less than candid. “During the course of this hearing these last four hours you’ve been asked several critical questions for which you don’t have answers,” Harris said.

With that in mind, we offer these suggested queries for House members:

1. How does Facebook track users when they’re not on Facebook?

Users are now accustomed to the notion that Facebook harvests every post, like, comment, and share to build profiles that inform the ads it displays to a user. But senators sounded a lot like ordinary Facebook users when they asked about whether, or how, Facebook tracks them when they are not on the social network. Consider this exchange with Sen. Roger Wicker (R-Mississippi).

Wicker: There have been reports that Facebook can track a user’s internet browsing activity even after that user has logged off of the Facebook platform. Can you confirm whether or not this is true?

Zuckerberg: Senator, I want to make sure I get this accurate, so it would probably be better to have my team follow up afterwards.

Wicker: You don’t know?

Zuckerberg: I know that people use cookies on the internet and that you can probably correlate activity between sessions. We do that for a number of reasons including security and including measuring ads to make sure the experience is the most effective, which of course people can opt-out of but I want to make sure that I’m precise.

Zuckerberg also got a lot of mileage from the line that Facebook doesn’t sell your data, until Sen. John Cornyn (R-Texas) shut him down by responding, “You clearly rent it!” Why not delve more into this rental agreement? The Wall Street Journal’s recent breakdown of all the data shared just to organize a pizza party is a good start.

Committee members could also ask about Facebook Pixel, its Like button, or other Facebook plugins that track consumers around around the web, even when they’re not logged in to Facebook. They could also probe more deeply about how data from Facebook gets combined with other sources, including shopping histories and public records.

2. Does Facebook behave like a monopoly?

Quite a few legislators asked tried to get Zuckerberg to admit that Facebook is a monopoly. Zuckerberg was asked to name Facebook’s competitors and identify a viable alternative for users who want to leave Facebook and go elsewhere. Zuckerberg responded that the typical American uses eight different communication apps, neglecting to mention that Facebook owns a few of those other apps too, including Instagram, WhatsApp, and Facebook Messenger.

A straighter route might be to ask Facebook about specific instances where it has allegedly engaged in anticompetitive behavior, such as brazenly copying Snapchat’s features or acquiring Onavo, a tool that help Facebook identify the next Snapchat it needs to buy or crush.

3. Pull out a laptop and ask Zuckerberg to walk us through the process of changing the privacy settings on a Facebook account.

This would be mostly for dramatic effect, but in keeping with this week’s corporate theater. But it would also prove a point. Zuckerberg repeatedly insisted that users own their own data, can remove it at any time, and can control who has access to it while they are on Facebook.

Exercising that control is not that simple, however. Start with Facebook’s 3,200-word user agreement. “I say this gently: Your user agreement sucks,” Sen. John Kennedy (R-Louisiana) told Zuckerberg. “The purpose of the user agreement is to cover Facebook’s rear end. It is not to inform your users about their rights. You know that and I know that.”

Then there are Facebook’s privacy controls, which are famously difficult to find and opaque. Warning: this question could go well over your five minute allotment.

4. Has Facebook prioritized growth over concerns about how users' data is handled, and have users suffered as a result?

Sen. Lindsey Graham (R-South Carolina) raised an infamous memo in which Facebook executive Andrew “Boz” Bosworth suggested that Facebook would tolerate extremists planning an attack on Facebook that kills people, if it furthered the network’s goal of connecting people. The real revelation of the memo is that Facebook pursued growth knowing full-well the potential dangers because the company viewed Facebook’s growth as a net positive to the world.

Zuckerberg said “most people at Facebook including myself disagreed with [the memo] strongly.” But the fact that it was shared undermines Zuckerberg’s claim to Congress and to the public that Facebook is an “idealistic and optimistic company.” Graham focused on the more scandalous bits, but it would be more instructive to ask Zuckerberg about times where users suffered because the company’s obsession with growth.

Facing Trouble

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