Here is what seems to be the 'catch' in FreedomPop's service:
"Unlimited voice, text & access to nearly 10 million nationwide WiFi hotspots."
It appears the 'unlimited' applies only if you are connected to an existing hotspot such as McDonald's, Starbucks or other WiFi providers that FreedomPop has partnered with.
Quote from FreedomPop's Terms of Service - Unauthorized Activities:
"...any action that imposes an unreasonable or disproportionately large load on our infrastructure or the infrastructure of our third party service providers."
They also can throttle or terminate service if they deem that you are using excessive data.
