Working in hosting I've found that providers pay primarily for traffic they offload to peers, not so much the traffic they take on. Typical user traffic is mostly download vs upload so that translates into more traffic verizon has incoming vs outgoing. That being the case, how they can justify charging $30/month for unlimited data is crazy. I'm all for stopping illegal tethering if it targets the heavy users because they are the reason everyone pays more to cover thier actions. Typical users don't do enough upload traffic to justify $30/month.
That being said...it's probably a waste of time and money for verizon to target light users of wifi tether.
That being said...it's probably a waste of time and money for verizon to target light users of wifi tether.