The only way they can afford to offer this is because they are forcing people to use wifi when available. So I could see them cutting off service to people who root their phones. As to inappropriate use, they have articulated clear standards for fair use here: http://www.republicwireless.com/home/pdfs/FairUsePolicyNovem... but the standards are based on proprietary info, so you won't be able to double check stats.
In other words, they must reserve a very big hammer to protect themselves simply due to the type of business they are trying to start. Said hammer could be abused, but they cannot not have it.
