A Slingbox and a wireless data plan are like oil and water because many carriers put a cap on data limits for your wireless data access. When overages like this occur it's generally an uneducated user blowing his cap out of the water.
An AT&T subscriber
uses his data card with a slingbox to stream cable broadcasts to his laptop. While sitting in the port of Miami about to set sail for a Caribbean cruise he wanted to watch the Chicago Bears play before he left for a relaxing vacation. After watching about two hours of the game the boat was leaving port and he didn't want to be charged roaming fee's so he turned off his laptop.