Vestager: I think that diversity is the most sustainable situation in any ecosystem. But the other thing, if you are a platform, you should have a number of obligations of transparency. People who depend on platforms constantly complain about them; we don’t know what happened, we don’t know why it happened, and we don’t know who to turn to. You’ve got to be a really big fish to get one of these companies to pick up the phone and answer questions. They have to be more transparent—and there needs to be some arbitration mechanism, so there’s someone to turn to. You can impose principles without going in and saying this is right and this is wrong.

Foer: Since so much of Big Tech’s power is invisible and it’s not even clear that they always understand the way that it functions, or at least they always claim their algorithms are so complicated that they don’t fully understand them …

Vestager: But that, I think, is another thing that you shouldn’t accept: that this is just a black box and what happens in Vegas stays in Vegas. It doesn’t make any sense. If it’s your algorithm, it’s your responsibility. This is the only way that we can sort of sustain a world where we know who is responsible for what.

Foer: We know they have a pattern of recklessness. Yet with their algorithms, it’s hard to establish fact patterns, to show cause and effect. I might have done something to offend, say, Amazon, and might be low in a search result. But why exactly did that happen? Were they punishing me? Or was the algorithm doing its job?

Vestager: But this is why we are setting up our hardware so we can possess enormous amounts of data. This is why we specialize our staff to be able to do this kind of analysis. This is why we work with market participants—for instance, in the Amazon probe that we’re doing right now, asking businesses and other stakeholders to provide us with data. That said, I think that reckless behavior, greed, power grabbing—when it comes to these motives, nothing is new.

Foer: Kara Swisher asked you about Elizabeth Warren’s plan for breaking up Big Tech, and you seemed hesitant. You don’t think the companies have reached the point where that kind of invasive treatment is warranted?

Vestager: My guess is Warren and I, we have, more or less, the same objective. So how to achieve that? Breaking up a company is a very far-reaching step. We have no experience of doing that in Europe. It’s something that you’ve done here in the U.S. We’ve never done it. I’m told that we could do it. We would have a legal basis. But for us, it would be very far-reaching. Also, you could end up in sort of a Hydra … isn’t that when you cut off the head and suddenly more comes out? That you split up a company, but instead of just one giant, then you have four.

Foer: But we were talking about diversity and pluralism. Having an oligopoly is still preferable to having a monopoly—at least those companies have some reason to compete to protect my privacy better or to supply me with information that better suits my needs.