Research conducted by VPN Mentor has found some VPN services, which are meant to protect us from prying eyes, aren't as secure as we thought. They tested three popular services and found all three to suffer from data leakage, including the real IP addresses of users.
The VPN Mentor research, which looked at Hotspot Shield, PureVPN, and Zenmate VPN, found that all three suffer from IP leaks that could allow governments, hostile organisations, or individuals to identify the actual IP address of a user while using one of the VPNs.
They noted that the vulnerabilities in ZenMate were less severe and that Hotspot Shield had already taken steps to better secure their service.
Choosing a VPN is largely an exercise in trust for most of us. Unless you have sophisticated test tools you are largely going on the documented policies and procedures of the providers and trusting their reputation. I've tried a few different VPN products and have paid for a subscription to Nord VPN which seems to work as expected but I am trusting them to do what they say on their website.
But VPN Mentor's research highlights that even trusted products and services can get it wrong and make mistakes.