A locksmith can copy a key, but cannot create a key that fits a specific lock without knowing anything about the key. In this case, they could create a key with the data Ford provided just using the "publicly available" (written on the windshield) VIN.
That key cannot be used to actually start the engine, because you need to register it with the ECU using manufacturer's codes and usually with at least one of the previous keys present. But there are bugs to be exploited in that case too.
Actually, they can add long as they have access to the lock itself. Take a blank key, insert and turn; find the dent made by the closest pin and for that place one level down. Repeat until you have a key that works. This is regarding the physical keys for the trunk.
That key cannot be used to actually start the engine, because you need to register it with the ECU using manufacturer's codes and usually with at least one of the previous keys present. But there are bugs to be exploited in that case too.