I've been wandering....I currently have an iphone 3g, this is just...dog slow...I've been looking online for a cheap 2nd hand iphone 4, I have actually found one that's only 2 months old but only half the price. My worry is, what is stopping the seller from lying to me. E.g., the phone he is selling me, is on contract and insured, by selling it to me, he can claim it's stolen, and then the phone I bought then becomes useless. Maybe I'm paranoid but how can I protect myself from this? As a sidenote, I have asked if he has the original receipt, he's said yes, so I guess that's not a problem, but are there any extra precautions I can take?