Data that travels over a public hotspot network is rarely encrypted. This means that every time you use public Wi-Fi, anybody who is looking can see everything you are doing. It enables them to access and rake through your emails, target you with specific phishing mails, call you with targeted messages and even capture and exploit your payment card details. The answer is a virtual private network (VPN) which creates a private tunnel between your device and the internet and encrypts your data. In short, you reclaim your privacy and can use the internet with total freedom and safety.”]
Source: https://securityaffairs.co/wordpress/90238/hacking/unsecure-wi-fi-danger.html