For work, that is blocked by a firewall. That's about the only time I tether or when I'm traveling and the hotel wants to charge me $4.99 a minute or some stupid amount for WiFi.
Tethering is fine. If you are on a tiered plan, VZW will let you tether all day long with no added fees.
But if you are on Unlimited, it is and always has been a violation of the TOS and the contract that you signed with them...
There really is no justification for stealing tethering, in a strictly legal sense... I mean, you signed your name on a contract that said that you can't do it... If you were not willing to adhere to it, you shouldn't have signed it, right?