Public hotspots, are they safe?

Last week, I was able to look into a very important part of my original work plan. I was able to look into the hidden dangers of public Wi-Fi, and if those public hotspots are really safe and really worth joining. This is an important aspect in my original work due to the fact that I want to create this box that doesn't allow cellular data and Wi-Fi signals to come in your phone, and I wanted a proven factor to show how unsafe these hot spots are.One of the most interesting factors in this piece, was that there are ways on my computer to download different firewalls and all these different things to protect some of the things and most of the things in public hotspots, yet phones don't really have that. They talked about VPN helping a little bit, but not much and it does not prevent. VPN prevents those hackings in those sniffings to happen inside of those public hotspots. Another very interesting piece, is it the Computer Fraud and Abuse Act, the cffa, mentions the stealing of data and the stealing of personal information being illegal and people will be punished. But the ways in which people do these things, or not. This is written in 2017, so the rules have changed, but with what I have looked up there hasn't been much change. What people do and the actions they do aren't illegal until they steal something. So people could just be watching what you do, and not get punished for it. This is with examples such as sniffing and man-in-the-middle attacks.With what I want to look into next week, is the Computer Fraud and Abuse Act in a more specific form, such as a lot of the details, and if it has changed in previous years.