: The screen is locked with a PIN. These are risky as they are often also iCloud locked. Why People Buy Locked iPhones
: The phone only works with one specific network (e.g., AT&T, Verizon). These are often "good deals" if you already use that carrier or can easily meet their unlock requirements . buy locked iphones
Buy locked iphones from internet auctions! - Apple Communities : The screen is locked with a PIN