I've never heard of Verizon monitoring peoples downloading of any material, let alone their actual usage. For the most part from what I've seen personally, and what some of friends say from their experiences Verizon expects people to use the bandwidth they are paying for.
Modelworks:
**Some people download 500GB a month and complain when the isp cuts them off.
Its true they shouldn't sell the accounts as unlimited, but some people have no respect for others and will abuse things any way they can. **
Its never been a matter of respect in any fashion. You sell a service that says unlimited in any way shape or form you better be prepared for people to use it like that. I have Verizon Fios 30Mb down / 5Mb up. I know there have been times that I've downloaded amounts that you would call excessive. However, no where in my service contract with them do they state any limits on my line. I am using my service as expected.
Just an FYI for you, Verizon Wireless in the last year got caught with selling people a service they claimed was unlimited on their air cards. They started terminating peoples accounts because of excessive usage. Guess what, they no longer advertise it as unlimited. Each aircard is limited to 5GB's of data download per month, its now in their TOS. If you pass that 2 things can happen 1st round warnning, or just straight cancelation.