The [US's] largest wireless carrier said Monday that it would begin locking the phones it sells to consumers, which will prevent them from using a SIM card from another carrier. Initially, the phones will be unlocked as soon as a customer signs up and activates the service. But later in the spring, the company will begin the practice of keeping the phone locked for a period of time after the purchase -- in line with the rest of the industry.
Verizon said it's doing this to deter criminals from stealing phones, often on route to retail stores or from the stores themselves. Unlocked phones make attractive targets because they can be resold on the black market or used overseas with different carriers. That's particularly the case for iPhones, which are a top target for thieves because of their high resale value.