I'm about to sell my iphone 4 on ebay because I had the AT&T upgrade available and I'm perfectly happy with my JB 3G. I'm now worried that selling an unopened Iphone to a stranger could be problematic. I'm guessing there's a sim card in the unopened box and I'm wondering if the buyer who receives it can activate the phone upon purchasing. If they do activate it with an included sim card will it have my information attached to it? I was planning on selling it unopened because I thought it would have more value, but if the sim card / activation will be problematic, I'm wondering if I would be better off opening the thing and jailbreaking it - while also removing the sim card. I'd like to also unluck it before selling but I'm hearing that this new iphone 4's firmware/baseband isn't quite ready to be unlocked. Can anyone please help me before I do something potentially stupid? Thanks in advance, sps EDIT: I still have my own sim card in my 3G and the upgrade was attached to a new 2yr contract. The new iphone4 that I want to sell is completely unopened and may or may not have a sim card in it as far as I know.