Source: Yahoo News
quote: The police officers dress more "streetlike" in a hoodie, jeans and sneakers and walk the streets of San Francisco with a bag of "stolen" iPhones to sell (the iPhones are actually borrowed from Apple for the purpose of the sting operations). He tells potential customers he has iPhones for sale, freshly stolen from the Apple Store, and that they should make him an offer (typically $25-$200). Buyers look the iPhones over to make sure they work, and once agreeing to the deal, offer the undercover cops cash. They accept, and give fellow police officers (who are parked down the street) a signal to make an arrest.