http://www.engadget.com/2011/03/18/...-using-unauthorized-tethering-methods-to-pay/ AT&T tells customers using unauthorized tethering methods to pay up or stop. Something to think about if you are getting the Wifi iPad and looking to tether to a jailbroken AT&T iPhone. I don't know if Verizon checks for it. At first I thought, how could they tell, but a comment to Engadget makes a good point: "If you browse the regular sites one would access on their phone, they probably couldn't tell. YouTube, facebook, twitter But usually there's all sorts of internet connectivity going on that you don't realize right away and I think that's how they get you. Your phone wouldn't connect to your anti virus program's update server, or to Microsoft's update server, or Apple's. Nearly every software checks for updates when it starts up (unless you disabled it, which most people probably don't do) so if AT&T find's any URL that has "update" in it, they know you didn't access that site on your phone. "