Technically: No, they are not vampires because the definition of a vampire and the definition of an AI are different. Ethically: No, they are not vampires because they may feed off of us, but it's isn't blood, it's information. The people they are learning from loose nothing by the exchange. We create them; we can destroy them. We can put in stop gaps and safety measures, or we can choose not to. Really, AI can't really be compared to ANY living thing, because a living thing has a will that we can't change or alter.