Jurisdiction – ZenMate is based in Germany, which is a country with one of the freest Internet in Europe. Online freedom is protected in the country and it does not have a history of persecution against bloggers and social media activists. Nonetheless, it is still part of the 14 Eyes alliance, which implies that users should be careful when considering ZenMate.

Free VPN Providers are more likely to log your activities and serve contextual ads while you’re connected. They’re also more likely to use your usage habits to tailor future ads to you, have fewer exit locations, and weak commitments to privacy. They may offer great features, but if logging and privacy are important to you, you may want to avoid them. However, if you just need quick, painless security while traveling on a budget, they’re a great option.
VPN services offer up different "gateway" cities, allowing you to choose where the IP address assigned to your computer is located. This allows you to access websites typically only available to users from that country. It also allows you to access websites that may blocked/censored in your own country. This application is particularly important for travelers who need to access websites from their home country, as well as for people living in regions rife with Internet censorship, such as China and Iran.
If the VPN client has a configured connection without a default route, the client adds a route that it infers from the Internet address class of the IP address assigned to it for the current connection. For a simple target network, such as a small office, this one route is sufficient to allow packets to be routed to the target network. However, for a complex network, administrators need to configure multiple routes to successfully direct packets to the remote network.
When we test VPNs, we use the Ookla speed test tool. (Note that Ookla is owned by PCMag's publisher, Ziff Davis.) This test provides metrics for latency, download speeds, and upload speeds. Any one of these can be an important measurement depending on your needs, but we tend to view the download speed as the most important. After all, we live in an age of digital consumption.
Bandwidth restrictions might not have been a big deal in the pre-streaming era, but now that everyone is streaming videos, music, and more, the bandwidth burns up really fast. Avoid VPNs that impose bandwidth restrictions unless the bandwidth restrictions are clearly very high and intended only to allow the provider to police people abusing the service.

So our advice is to not use a free VPN unless it really is for occasional, very casual use. For the odd IP-hopping use case, they can work. But if you're planning on using the VPN a lot and for streaming video etc we'd highly recommend going for one of the overall best VPN services - they're not free but they're also pretty cheap in the grand scheme of things.
Are you so used to your data traveling over Wi-Fi that you've stopped worrying about the security of that data—and about who else might be spying on it, or even stealing it for nefarious purposes? If so, you are—sadly—in the majority, and you ought to consider using a viritual private network, or VPN. In fact, when PCMag conducted a survey on VPN usage, we found that a dismal 71 percent of the 1,000 respondents had never used a VPN. Even among those who support net neutrality—who you might think would tend to be well informed on technology and privacy issues—only 45 percent had used a VPN.