Paying for a virtual private network (VPN) service provides users with many benefits, including encryption of their online web traffic. Keeping your sensitive data private is its primary function, and in the vast majority of cases, that’s how they work.

This doesn’t necessarily seem like a bad deal for users. This apparently includes all the benefits of a VPN, including tunneling through nodes in other countries to bypass geo-limitations on content.

However, even though free is a great price, it certainly doesn’t mean you’ll get good service. In some cases, this does more harm than good, for many reasons.

Most of the best subscription-based VPNs boast high standards when it comes to encryption. Using high-level encryption that is regularly verified and tested, paid services go a long way to assure customers that their data is safe.

However, the better the encryption, the more expensive it is to implement and operate. For a free VPN that doesn’t necessarily have the cash reserves to do this, it’s simply not possible.

Instead, free VPNs end up using older protocols. One of the most common is PPTP (Point-to-Point Tunneling Protocol), which is no longer exactly the most secure method to use online.

Weak protocols are more easily broken by a determined attacker, meaning your traffic is at risk.

Another reason not to use free VPN services is how they can generate income. To compensate for your use of their services, they must use all the data they collect to recoup the cost.

This usually means that your activity is recorded. Although your actual connection may be private from prying eyes, the service may collect your browsing history and other personal information that it can detect.

This data is then sold to data brokers, who are then used to create profiles that online marketers can use to target advertising to you. It is even collected and used by government agencies.

This is pretty much how Google earns revenue while providing many free online services, and pretty much everyone is aware of what’s happening. The difference is that you don’t expect a service like a VPN to actively collect and share your data when it is intended to keep your online browsing private.

As usual, if you use a free online service, you are often the real product.

Paid VPN services often emphasize that they do not collect data about their users in this way. Not only because they don’t work with data brokers, but also because of the privacy risks.

If a VPN collects data about your browsing habits and stores it, this data cache becomes a potential target for hackers.

A VPN service with lower-quality encryption and data logging capabilities could go even further to recoup its revenue. They could interfere with web traffic itself.

This does not mean large-scale falsification of web search results and the content of the website you wish to view. In fact, a free VPN may insert additional elements into pages or as pop-ups, so that you may receive advertising.

These ads would generate revenue for the free VPN service itself, not the website where the ad was placed. It is also plausible that real advertising on a website can be replaced by the use of unscrupulous free VPN services.

In the latter case, this would mean denying the website you are visiting advertising revenue.

This is actually a bigger problem than you think, beyond getting more ads. It is possible that these ads deliver malware directly to the browser because it is added through ad networks that are less safe and secure than traditional networks.

The worst problem with free VPNs is if you choose one that is actively malicious. Accessing a free VPN is a big carrot that a hacker could use to catch unsuspecting victims who are only too willing to install the VPN app.

This application may contain malware, hidden so that it can be installed without your knowledge. This malware could, in the worst case, collect and send your data or infect the system on which it is installed.

Well-known, paid VPNs obviously don’t have this problem, as it would seriously damage their reputation. A barely known free VPN doesn’t have that to lose.

The issues described above are common problems for free VPN services, but not all have these issues. Besides paid services offering better levels of security and encryption, you can always find free and safe services to use.

Some free services are actually freemium, referring to paid services that offer free tiers of usage. Although limited in various ways, such as server selection or speed, they often offer the same type of security as the paid version.

A considerable exception in the Free VPN world is ProtonVPNthe service from the same people who created ProtonMail. Although the free options limit the servers you can use, they still use excellent encryption and have a strict no-logging policy.

If you only need a VPN for occasional tasks and aren’t quite ready to pay for a full-fledged VPN, ProtonVPN is a decent option for free protection. You can also find discounted prices on paid VPN services with Black Friday VPN deals.