'Unlimited' 3G broadband access really is unlimited.
There are always some conditions attached with Free" or Unlimited' services. Some providers' terms of service forbid users from uploading or downloading files, viewing webcams, or using Voice over IP services. Some companies even have an undisclosed 5GB cap on each account and if they detected that you have sent or received more than that in a given month, it will terminate your contract. There is no such thing like Unlimited' or Free'.