said by chgo_man99:P.s. only like maybe 10% people or less know about "free tethering" and jailbreak or root devices. Its kind of a "secret" that will never be out and probably its good that it won't otherwise carriers would be harder trying in preventing users from jailbreaking. You have not only users that may not know how, but also those that don't want to assume "risks" and void warranties. If something happens with your iphone and its jailbreaken and bring it to Apple genius, they won't help you. And in effect they voided warranty unless it was already purchased over 1 year ago without extension. Yes you can restore it to stock software or hide cydia app from dashboard before you bring it but what if you can't access screen, its blacked out, its still within warranty and want to bring it to service.
I don't know whats the policy on Android rooted devices but I imagine its similar.
No jailbreaking needed if Karl's story is correct and Verizon will no longer charge for or prevent tethering under their new pricing plans.