NFC of credit card information scares me just a little. Thieves can easily walk by someone, "brush" into them and retrieve this information. I'm glad I have a passport that was created before the NFCs were installed so I don't have to worry about it. Alternatively, this will make the market for lead iPhone cases boom...![]()
On the contrary, a smartphone based NFC is a lot more secure than one on a credit card or passport. Those are passive systems that are activated by the proximity to an energy source (the reader) where as an iPhone NFC system would be active. You could turn it off completely when not in use and even require a pin be input into your phone to authorize the transaction.
An example: you go to your local coffee house, pull your phone out to pay, scan over the reader and a pop up asks: "Payment $3 to Starbucks? OK | Cancel". For larger payments, you'd be required to input a PIN. Also, you could turn off the NFC chip completely and require that you open an app before scanning your phone.
It's very safe.