I'm pretty sure I have purchased a stolen iphone

I'm pretty sure I have purchased a stolen iPhone. But I'm still trying to get into it, it says " this phone is linked to a Apple id. Enter the apple id and password that were sued to set up this iPhone". Is there a way i could hack this and maybe get the phone to start working? I already tried to take out my own sim card and put it in this phone it is not working. I told the person i bought it from that it was not working and he told me that he forgets his apple id but i'm pretty sure that this is a stolen device. None the less i still paid for the phone and if he is not the original owner i have no idea how to contact them and at the end of the day i still need a phone eventhough it is morally wrong. ( SORRY) . Could anyone give me any advice on how to get into this phone?!

Sadly you are stuck with a phone that you can't EVER, use on any carrier in the US, Canada, Mexico, Europe and most of Asia and South America. So if the seller is unwilling to take the phone back and give you a refund, you have wasted your time, and money on this phone. You can go to any of the IMEI / ESN checkers on the internet to check to see if the phone has been Blacklisted, a sure sign that the seller knew beforehand that the phone had been reported lost or stolen to the carrier by the original owner.

IMEI Info
http://www.imei.info/

First, from the error message, it might not be stolen. The idiot locked it with a password and maybe forgot it. If that's all it is, you can take it to a non-apple phone shop and they might be able to reflash it to near factory specs and get around that. The process will also "jailbreak" the phone, so it won't be locked to the original provider.

Of course, if it *was* reported stolen, the phone's IMEI would have been blacklisted on all networks on the continent (some providers report it globally). You can't really get around that. The IMEI on production phones is hard coded into ROM, and can't be easily changed -- it's an anti-theft feature. Only the original phone provider can request that a phone be taken off the list as they are the legal owner of the stolen phone. Whether or not you paid money for it or not is irrelevant.

Sorry, but if the phone's stolen, even if you get past the password lock, all you've got is a legally iffy, combination mp3 player/camera/paperweight. The non-phone and non-data features should still work, so any apps already installed should still function in offline mode.