This is the exact restrictions on Verizon's website:

UNLIMITED DATA PLANS AND FEATURES
Unlimited Data Plans and Features (such as NationalAccess, BroadbandAccess, Push to Talk, and certain VZEmail services) may ONLY be used with wireless devices for the following purposes: (i) Internet browsing; (ii) email; and (iii) intranet access (including access to corporate intranets, email, and individual productivity applications like customer relationship management, sales force, and field service automation). The Unlimited Data Plans and Features MAY NOT be used for any other purpose. Examples of prohibited uses include, without limitation, the following: (i) continuous uploading, downloading or streaming of audio or video programming or games; (ii) server devices or host computer applications, including, but not limited to, Web camera posts or broadcasts, automatic data feeds, automated machine–to–machine connections or peer–to–peer (P2P) file sharing; or (iii) as a substitute or backup for private lines or dedicated data connections. This means, by way of example only, that checking email, surfing the Internet, downloading legally acquired songs, and/or visiting corporate intranets is permitted, but downloading movies using P2P file sharing services and/or redirecting television signals for viewing on laptops is prohibited. A person engaged in prohibited uses, continuously for one hour, could typically use 100 to 200 MBs, or, if engaged in prohibited uses for 10 hours a day, 7 days a week, could use more than 5 GBs in a month.

For individual use only and not for resale. We reserve the right to protect our network from harm, which may impact legitimate data flows. We reserve the right to limit throughput or amount of data transferred, and to deny or terminate service, without notice, to anyone we believe is using an Unlimited Data Plan or Feature in any manner prohibited above or whose usage adversely impacts our network or service levels. Anyone using more than 5 GB per line in a given month is presumed to be using the service in a manner prohibited above, and we reserve the right to immediately terminate the service of any such person without notice. We also reserve the right to terminate service upon expiration of Customer Agreement term.

Verizon Wireless Plans, Rate and Coverage Areas, rates, agreement provisions, business practices, procedures and policies are subject to change as specified in the Customer Agreement.

Last Update 03/15/07

link: http://b2b.vzw.com/broadband/bba_terms.html