Hi guys, I know that a bad esn means that a phone has been stolen or lost and can't be activated. There is a lady on craigslist offering to sell an iPhone 4 16 gb for a very low price (around $50). What can I do with the phone? Is it permanently unusable? can I use it with other carriers? would I have to get it unlocked to use it? is there a way to clear the ESN?