Someone I know was waving an iphone 5 around, commenting, I asked if he had just bought it.
He replied he had and that it only cost him £30.
It transpired a visitor to his premises had offered it to him along with a blackberry and new Nokia, he bought all three for £30. The visitor, a taxi driver had quite a business.
He passed the other two on. However the iPhone was password locked so he phoned Apple for an activation code claiming he had forgotten his account details. In his own words, "when you phone Apple and talk to someone who sounds sharp and awake, put the phone down, try again until you hear someone who sounds like he couldn't care less, then ask for the code."
It took him less than 15 minutes to activate a lost/stolen phone.
I wonder if this can be used on the 5S