When you want to hide web activity from your ISP or cellular carrier, a VPN is usually the go-to option. But even when your web activity is hidden behind a VPN, your ISP and carrier can see how much data you're using. A VPN will not circumvent your monthly data cap, and it will only bypass certain forms of data throttling.

This Cybersecurity Awareness Week article is brought to you in association with Incogni.

VPNs Hide Your Activity, Not Your Data Consumption

A virtual private network (VPN) routes your internet traffic through a remote server. In effect, you take on the VPN server's IP address and location. Websites have a hard time identifying and tracking you when you use a VPN, as they can only see the VPN's identifying details.

But websites aren't the only threat to your privacy. Your internet service provider (ISP) or cellular carrier can observe everything you do online. And if a hacker manages to intercept your internet connection (through public Wi-Fi, for example), they could collect your login credentials and other sensitive information. A VPN protects you from these parties by creating a "secure tunnel" that encrypts your web activity. When you use a VPN, your ISP and cell carrier can see that you're online, but they can't see what you're doing.

That said, a VPN can't hide your data consumption. Your ISP and cellular carrier can always tell how much data you're using, even when your activity is masked. In fact, a VPN can actually push you closer to your data cap. The encryption process utilized by VPNs increases your data consumption by up to 15%.

If you regularly exceed your monthly data allotment, you must upgrade to a more expensive plan or simply reduce your data usage. We recommend that you start with the latter option and see how things shake out. Streaming services are usually to blame for excessive data usage, so don't leave Netflix running all night, take advantage of the offline downloads feature in your favorite streaming apps, and reduce streaming resolution when possible.

A VPN Can Bypass Some Forms of Data Throttling

Your ISP or cell carrier may not charge you a fee when you exceed your monthly data allotment. Instead, they may reduce your internet speeds for the billing period. A VPN won't help you get around this problem—again, VPNs don't hide your data consumption, so if you regularly hit your data cap, you need to switch plans or change your habits.

However, a VPN can bypass some forms of data throttling. Internet service providers are known to throttle connections to streaming platforms like Netflix. And if you're on an inexpensive unlimited plan, your cellular carrier may force you to view streaming content at a low resolution. A VPN prevents your ISP or cell carrier from seeing the websites you visit, so using a VPN is often the best way to circumvent these restrictions.

Note that a VPN connection will normally reduce your internet speed. You'll only notice an increase in speed on websites that are actively throttled by your ISP or cell carrier. If you suspect that a specific website is being throttled, try using a VPN to see if things improve. Avoid free VPN services, as they're incredibly slow and may actually decrease your privacy.

Does Your ISP or Carrier Know That You Use a VPN?

The connection between your computer and your VPN is encrypted by a secure tunnel. Your ISP or cell carrier can see this stream of encrypted data, but because it's encrypted, it looks like a bunch of gibberish. Your ISP or cell carrier cannot decrypt this data, as it would take at least a billion years to do so with current technology.

In any case, a stream of encrypted gibberish is a tell-tale sign of VPN usage. Your ISP and cell carrier know when you're using a VPN—they just don't care or can't do anything about it. You might use a VPN to watch out-of-market sports games, but VPNs are also a key component of corporate and government cybersecurity. So, VPNs must be tolerated.

That said, your campus or workplace may block your internet connection if they detect that you're using a VPN. Authoritarian governments also tend to outlaw or restrict VPN access, though the actual enforcement of anti-VPN policy can vary wildly, and the rules aren't always clear-cut for international travelers or those involved in foreign business.