VPN's aren't specifically that safe alone. Usage of them to bypass bandwidth restrictions could possibly be made illegal, and like I said in the sentence before, you can't just hide behind one. But i'm sure if net neutrality was repealed, illegal services would probably start popping up. Also the thing that scares me the most would be the fact that ISP's could monitor your traffic and receive info about things that you do on the internet and monitor and charge access to them accordingly.

ISPs can already monitor your traffic. It's not hard to do, you can literally find out everything that's going on in a public network using a laptop with wifi and a packet sniffer. I may not be able to use the encrypted information stored in the packet, but I can figure out where it originated from and where it's intended destination is just by reading the packet header, and that's more than enough information to start establishing an idea of what services people are using.