iphone 4 off craigslist

i think i bought a iphone 4 thats stolen on craigslist.
he said it was unlocked iphone 4 but when i put my sim card in it, it doesnt work

I read up on some stolen iphone facts and the law says it doesnt matter if u knew it was stolen or not, if you're in possestion of a stolen item, you're at fault.

So now that i put my sim card in it, will my carrier or apple know that i am carrying a stolen iphone now and will they take action?

im about to email that guy i bought the iphone off of and get him to return the transaction

Here are your options at this point:

1) You can attempt to return the device to the seller, however, if the phone really is stolen, you'll have a hard time getting the return processed.
2) You can contact local law enforcement and report that you believe you have been conned into buying merchandise that may be stolen. Provide them the serial number and other identifying information about the device, and then have them work with you to retrieve the money you spent from the seller. You will most likely have to turn the device in to law enforcement for the duration of any investigation, however, when the investigation is complete, they may return the phone to you.

The law you read is mostly correct, though there are mitigating circumstances that can turn that black and white issue into something with more shades of gray. If you believe the device is stolen, it is your responsibility to bring it to the attention of law enforcement. If you remain the owner of the device after you believe it's stolen, you become an accessory to the theft or at minimum can be charged with possession of stolen property. The only legal answer is to return the phone to the person you bought it from or to local law enforcement.

If the IMEI was blacklisted, it is definitely possible that the carrier is aware that you have inserted your SIM card into it and attempted to activate it, but I believe the possibility of them taking any action is nearly 0%, as there are other (non-criminal) reasons for a phone to be IMEI blacklisted or blocked.

Since when does Apple or a provider blacklist stolen iphones? My iphone 4 was stolen and Apple told me to f**k off(politely of course) when I asked for help(they do not black list nor do they care). The two local providers(Fido and Rogers) also do not give a damn, and they do not blacklist. So whoever has my stolen phone simply restored it and is probably using it.

Apple does not blacklist stolen iPhones (no one claimed contrary), but IMEI and MEID blacklisting are in place both in the US and the EU. The EU has an amazingly far reaching IMEI blacklist system that prohibits blocked IMEIs from even receiving service on the tower across nearly the entire EU (which is part of the reason that the discussion of IMEI tampering and changing is not allowed on these forums), and Verizon and Sprint employ MEID blacklisting in the US for stolen devices as well.

Please research before posting -- both the IMEI and MEID blacklisting practice has been around for many years. You are correct that Canadian carriers do not yet employ an IMEI blacklist, but it is naive to think that just because they don't blacklist where you live that they don't blacklist anywhere else.