IP Address: Not as Private as You Think
Your IP address is a number assigned by your Internet Service Provider (ISP) to every connection you make to the Internet. Contrary to popular belief, it’s not always unique to your personal device, nor is it a permanent ID. In fact, it can change over time and sometimes be shared among multiple devices (especially if you’re all binge-watching the same show at home!).
This identifier is used to relay information across the Internet, allowing websites and online services—not to mention advertisers—to display content directly on your connected device. Yes, that means everything from the latest headlines to those mysteriously accurate ads for running shoes.
Device Identifiers: Much More Than Cookies
Beyond your IP address, there are other ways websites and apps figure out who you are—or at least, which device you’re using. A device identifier is a unique string of characters usually assigned to your device or browser using cookies or other storage technology. This identifier can be created or read by websites or apps to recognize your device, whether you’re browsing the same site over and over, or bouncing between different apps and web pages.
Probabilistic IDs (a.k.a. The Fingerprinting Game)
If you combine the technical characteristics associated with your device (say, your browser type or operating system) and your IP address, you get what’s called a probabilistic identifier. Add in other features—like your installed fonts or your screen resolution, provided you give your consent—and this digital “fingerprint” gets even more precise. However, the ID remains probabilistic because several devices can share the same features and Internet connection (think roommates on the Wi-Fi).
This type of ID helps companies recognize your device across different websites and apps—sometimes even if you aren’t logged in. (Big Brother, but in high definition?)
Your Online Activity: More Revealing Than You Think
- The things you do online—like the websites you visit, the apps you use, what you search for, and what content or ads you interact with (including how many times you see or click on something)—all get noted.
- If you fill out online forms, such as surveys or feedback or create an account (say, sharing your age or job), those details are now in the mix.
- From what you do and share, characteristics about you can be guessed or modeled—for example, your potential interests, your likelihood to shop for something, or your broader consumer profile. All from that digital trail you leave behind.
- Your location? That’s not immune either. An approximation of your whereabouts can be clocked thanks to your IP address—usually as an area with a radius of at least 500 meters (about a third of a mile). Not pinpointing your living room, but maybe your neighborhood Starbucks.
Plus, some identifiers can be created based on your authenticated data. For instance, if you sign up for an online account with your email or phone number (or use a user ID from your telecom provider), the site or app can recognize you on different devices or platforms—provided you log in with the same details.
What Does All This Mean for Your Privacy?
Put simply, your IP address and these identifiers are used by services and advertisers to route information, display content (and ads), and personalize your experience across the online world. However, as handy as all these identifiers are for streaming the next episode or getting those eerily on-point ads, they do mean your online behaviors say more about you than you might realize—even if you’re not logged in anywhere.
So next time you connect to Wi-Fi at that café, know that your digital handshake is saying hi to more folks than you think.
