theres nothing illegal about using unlimited data your paying for. verizon wants you to pay for the option to tether. so they can profit from it. can they tell its happening almost certainly. now if all your traffic is encrypted can they prove it? probably not.
You sir are quite misinformed. It is in fact quite illegal to tether your phone without paying for it. Of course Verizon wants to profit from it, they're a business and in business the object is to make money. Supply and demand, they have something you want, you pay to use their service.
The simple fact is, whether you agree with it or not, Verizon has decided to charge for the ability to tether and in fact assigned a completely separate data plan to that function.
If you decide that you want to tether without paying for it you have to actively pursue a course of action to circumvent their system and then you are using a service you are not paying for.
You can justify any number of reasons for why you think Verizon's wrong to charge for tethering but the fact remains you are using their system and as such you are subject to their terms of service which includes following their rules. One of which happens to be that if you want to tether, you agree to sign up for a data plan to do so.
Its not like this is an original idea and Verizon is the only company charging for this service.
I try not to judge people or their actions. If you want to do that, you're a big boy and know the risks, go for it. Just be ready for the consequences and don't come back all surprised and butt hurt if you get caught.
What bothers me is when people put out blatantly wrong information which might get someone into a jamm. Don't let personal opinions or beliefs muddy the waters of legality.