You’re probably aware that US Internet providers will fight tooth and nail to be able to sell your browsing habits for a profit. If not, the best example of this behavior is when ISPs sued the state of Maine for daring to protect the privacy of its citizens. Using a VPN in the US is pretty much essential if you don’t care to share your online habits with shady advertisers.

Of course, you’ll need a capable no-logs VPN for the job (such as these ones https://proprivacy.com/vpn/comparison/best-usa-vpn). Otherwise, you risk running into the same problems with “free” VPN providers. Just last year, several such providers leaked the data of 20 million people online, despite claiming to keep no logs of user activity.

Still, it’s fair to say that not even top-tier VPNs can make you completely invisible on the Web. Sure, the data ISPs can see about you while using a VPN won’t put your privacy at risk, but it’s worth keeping informed all the same. In any case, here’s what they know.

#1 Your and the VPN Server’s IP Addresses

Your IP address can reveal a lot about your real life location – your country, city, and even your ZIP code. VPNs mask your real IP address and assign a new one based on what server you connect to. Not only is this a benefit to your privacy, but it also helps you get past geo-blocks and access content from abroad.

However, a US VPN can’t hide your real IP and location from your ISP – after all, they’re the ones who assign it to you. Also, they still know who you are and where you live (how else are you going to pay the bills?)

They’re also aware of the IP of the VPN server your device communicates with. Fortunately, that’s about it. For all intents and purposes, your IP only ever “contacts” the VPN server, and your ISP can’t see what websites and network-capable services you use.

#2 An Encrypted Data Stream

Even if you haven’t seen The Matrix, you probably know that distinctive green digital “rain” effect. Now, the data stream that makes up your online activity may not look that cool to your ISP (or other third parties snooping in on you), but it still looks like gibberish.

In short, there’s nothing to worry about. Your encrypted data holds about as much value to advertisers and hackers as a GIF file of The Matrix rain effect.

The only country in the world where people would’ve had anything to worry about is Kazakhstan. Why? Well, in 2019 the government forced local ISPs to get their users to install root certificates on their devices and browsers – lest they risk losing Internet access. These certificates would have allowed them to see all encrypted traffic, including HTTPS traffic. Fortunately, these plans were later abandoned.

#3 The VPN Protocol You Use

There are a fair number of VPN protocols out there, each with its own strengths, speed, and level of security. We won’t go into detail about what each one does, as that’s beyond the scope of the article. However, we will say that each protocol uses a particular port number, so your ISP can infer which one you’re using. For example, OpenVPN – the most commonly used protocol at the moment – runs on UDP port 1194 by default.

Certain ISPs or public Wi-Fi providers may choose to block traffic for services according to the port number. Say, blocking ports 27000-27030 on a university Wi-Fi network, to prevent students from downloading and playing Steam games.

Schools and workplaces may also choose to block VPN traffic that way, though it’s less likely. Fortunately, this can be easily avoided by setting up the VPN with port forwarding. Essentially, redirecting traffic to a different port – usually port 443, which is used by HTTPS traffic. This makes VPN traffic virtually impossible to block without affecting most regular traffic.

#4 VPN-Related Metadata

First off, your ISP can see the exact time you connect to the VPN, as they can see when your device starts communicating with the VPN server. On top of that, they can see how much data is transferred between you and the VPN.

All this data passes through your ISP’s servers in an encrypted form, of course. They can see you used up 30 GB of data on a certain day; they just can’t tell what it consists of. No browsing data, none of the videos you watched, none of the files you’ve downloaded. Just a big chunk of gibberish.

Unfortunately, this means you can’t get around data caps by using a VPN in the US. Yes, we know, data caps are a silly practice. Despite that, VPNs continue to be a useful tool, both for your privacy and entertainment needs – so give them a go, using the link provided at the beginning of this article.