You may think you're discreet about your politics. You may make an effort to keep your opinions off social media. It doesn't matter: Facebook has decided, based on your friends and interests, what it believes your political sentiments are.

At least now you can see how you're being labeled. A helpful New York Times article has supplied this link that you can follow to learn what the social media giant thinks about your politics. You should do this on a computer, not a mobile device. Make sure you're on the first tab, "Lifestyle and Culture." If you don't see "U.S. Politics" among your choices of interests, click on "More". (If Facebook thinks you have lots of interests, you may have to click "More" several times.)

I tried it, and learned the site thinks I'm "very liberal," even though I mostly don't express my political opinions on Facebook. If you asked me, I would probably say I'm somewhere between liberal and moderate. But Facebook is drawing these conclusions about me--and you--based on who my friends are and on the things I seem to like. For example, I practice yoga and eat organic food, although I'm not sure how Facebook knows this.

What if Facebook has things wrong and you want to tell it to change your political affiliation? You can't do it in ad preferences. I find I can click on a frownie face to say I'm "no longer interested" in "very liberal," but that seems to be the only choice I have. Although if I joined a Trump-supporting group or liked a Fox News page in my profile, Facebook would take note of that and might change my category.

Why is Facebook categorizing us all by presumed political affiliation? Advertising, of course. With the general election less than three months away, political candidates, parties and PACs will spend billions on advertising. Much of that advertising revenue will go to Facebook, especially since the number of Americans with broadcast television subscriptions is dwindling. That's especially true for Millennials, a cohort all political parties are eager to reach. Advertisers pay to reach people with specific political views--for instance the Trump campaign is paying to have moderates see its Facebook ads, according to the Times.

This kind of thing continues the trend of fragmenting what all of us see and hear based on the beliefs we already have, taking advantage of the psychological phenomenon of confirmation bias. We gravitate toward information that confirms what we already believe and shy away from anything that makes us question those beliefs. This is good for advertisers and for Facebook--we're more likely to click an ad for a candidate we already like--but not so good for getting a balanced view or creating discourse across the political spectrum. It's just one more element that creates the fragmented, polarized, political climate we all live in now.

What do you think of Facebook categorizing you by your politics? And is it right about your political leanings? Let me know in the comments if you check out your own Facebook political profile and what you think about it.