When Mark Zuckerberg gave a speech at Georgetown University last week on the virtues of free expression, he said all of the right things. Unfortunately, talking about a commitment to free expression is meaningless without taking steps to actually ensure that your platform allows it.

"While I certainly worry about an erosion of truth, I don't think most people want to live in a world where you can only post things that tech companies judge to be 100 percent true," Zuckerberg said at the event, which was live-streamed on his Facebook page. But, no matter how often Zuckerberg, Facebook's CEO--or anyone else from the company for that matter--talks about free expression, the reality is that Facebook itself is a huge threat to free expression.

Here's why: Facebook acts as the arbiter not of what is true, but of what you see in the first place.

The Algorithm Problem

In that sense, Facebook already decides what is true. Every day Facebook's algorithm decides what you see in your News Feed. Every day it makes the choice for you about what it thinks you care about and feeds you what it determines will generate the most engagement. That's how the company makes its enormous profits, by keeping you engaged so that it can show you more ads.

Facebook would argue that the 100,000 or so factors that it uses to decide what to show you in your News Feed are designed to serve you the exact content that you care about most, and as such, it's actually doing you a favor. 

Make no mistake, the algorithm is designed to serve Facebook's purpose. Sure you end up seeing some content that you might otherwise miss, but only because Facebook decided you should see it. In doing so it not only stifles free expression, it actually moves the conversation in the direction of whatever drives the most engagement.

How exactly is that free expression? 

Engagement at the Extremes

The problem is that engagement comes not from what we necessarily care about, but from what we experience as extreme. People comment on the things they most agree or disagree with, most often the latter.

Every day I'm interested in hundreds of Facebook posts I never take any action on. It's only when someone says something I really disagree with, or something I feel especially passionate about (positively or negatively), that I take the extra effort to engage. That engagement, while good for Facebook, isn't the best barometer of what truly matters to my ordinary life. 

Facebook's algorithm reinforces that engagement with more of the same content. "Like" a political post? You'll see more of the same. Share a friend's post? Somehow their content will show up more often. Did that friend suddenly start using their right to free expression more? No, Facebook just decided to let their posts take over my News Feed.

The type of content Facebook presumably wants to discourage (divisive or harmful content, for example) also happens to be what generates the most engagement. The sensational always attracts attention, which feeds the algorithm, which attracts more attention.

Worse Than Censorship

It doesn't matter whether Facebook actively censors certain viewpoints, the result is actually far worse. Facebook is deciding--on your behalf yet without your input--what you should see based entirely on what it thinks is best for you. Not only do most people not want tech companies deciding what is true, I don't know anyone that wants those same companies deciding what is best for them.

I get that Facebook is in a difficult position. Its platform is enormous, and it's increasingly difficult to create policies that prevent abuses by bad actors. On the one hand, the company wants to allow free expression up to the point where it could actually cause harm. (That's Zuckerberg's explanation, anyway.) At the same time, Facebook seems to completely ignore the fact that it already directly affects which forms of expression you are exposed to every single day.

And, it does so in a way that is most profitable for itself.

That isn't free expression by any definition. And the fact that Zuckerberg publicly promoted the company's commitment to free expression without addressing that obvious fact tells you everything you need to know.