Any transaction issued with Bitcoin cannot be reversed, they can only be refunded by the person receiving the funds. That means you should take care to do business with people and organizations you know and trust, or who have an established reputation. For their part, businesses need to keep control of the payment requests they are displaying to their customers. Bitcoin can detect typos and usually won't let you send money to an invalid address by mistake. Additional services might exist in the future to provide more choice and protection for the consumer.