Originally posted by JB
Many moons ago in the iPhone OS 1 days, there was a chance jailbreaking would brick your device, but that simply does not happen any more, there's always a way to restore it to a working state should something, if anything, go wrong. The jailbreak does void your warranty with Apple, however if you completely restore your device in iTunes to the latest version of iOS, it will completely remove the jailbreak. Apple are also unable to detect whether the device has been previously jailbroken.
Do I have to remember all my Passwords and e-mails of iCloud and iTunes jailbreaking my devices? Does ti requires this things?