I use it too, and have just experienced how wonderful their customer support is thanks to a stolen card (online unauthorized charges, likely via a web store I used recently). I was alerted to the charges thanks to the app alert, which is really fantastic. They fixed the problem swiftly and sent me a new one without charge. Very pleased with the good service. Plus I'm not aware of the lock function in the app so I'm going to keep the new card locked unless I want to use it, thus avoiding future possibility of fraud.