I will say off the bat I haven't used it but am sharing why. It seems a great idea to generate virtual numbers to protect your own, but in the fine print it says that they haven't yet been able to limit use of a number to one merchant or transaction, and that each virtual number is live, meaning that a bad employee of a merchant I use could still use that number for a purchase. Ultimately, until a better version comes along, it seems to me that Eno makes it easier for Capital One to track reported fraud, but for the consumer it just multiplies the number of card numbers out there which all point back to my card and make me responsible for payment. Maybe a future version will sort this out! I will stay tuned.