Targeted advertising and targeted news feeds are commonplace online. Services try to tailor what they show to keep you interested so you’ll spend more time on their site, and hopefully, click more ads. Using the information from how you react to what they show you, they build a profile of your interests to better tailor what they show you. Unfortunately, those services don’t have an interest in making sure you see a neutral view of the world or even that you see every post from the people or brands you follow. They’re interested in providing results that are relevant to you, whether or not they’re always correct, so they can gather more information and continue selling advertisements.

Interest targeting takes a lot of different forms online. The most obvious is online advertising, which comes as no surprise to people accustomed to the Internet showing them ads for things they searched for recently. Much of the online economy and free-to-use services rely on this to fund websites. Some services sell ads directly, while others sell the targeting information itself. The same data is used by services to learn your tastes so they can suggest events, local restaurants, and other things to you. Data gathering for better targeting is expanding as tracking moves towards mobile devices that people carry with them, providing location and habit information beyond what can be tracked with a home computer.

Targeting has made its way past ads and suggestions and into news feeds and to a degree search results. Services curate what they show based on what they think you’re interested in. The fact that they do this is likely unsurprising, but the degree to which they do it is much larger than is immediately apparent. Social media is similar, hiding certain posts from the things and people you follow if the site thinks you’re not interested. The resulting feeds can make it difficult to get honest information if the facts don’t match what a site thinks you believe. Worse, it can lead to an effect known as the Filter Bubble where sites confirm what they think you think, no matter if it’s grounded in any sort of reality or not. The sites you use may be choosing what you see without you realizing it.

With some effort, it’s possible to escape your bubble. However, targeting has a deeper effect than trapping you in your own online reality. Targeted advertising, aside from its intended effects of convincing you to support or buy from a particular brand, can manipulate your thinking if you think it’s targeted. In a study, people shown an ad for something eco-friendly or sophisticated rated themselves as more eco-friendly or sophisticated, respectively, if they thought the ad was targeted to them. The caveat was that the targeting had to be at least slightly accurate to be effective, but it showed that ads have an effect even if we know—or at least suspect—that they’re targeted to us.

By targeting users, or by pretending to target users, it’s possible to encourage a service or view over another. There are no neutrality regulations for online services so a site could push an agenda by showing only a certain type of ad. Sites that provide a tailored feed—including Google and Facebook—keep their algorithms secret so there’s no real way to know if they’re actively hiding something from you. This is dangerous for the future of democracy as more people rely on the Internet for news and information. The tailoring that tech giants market as an improvement to our online lives may actually be making it harder to be informed, especially since the tech sometimes gets things wrong.