This is such a useful feature to have for my Capital One cards. It gives me peace of mind when I shopping online. I have dealt with fraudulent transactions on a different credit card and it's such a headache. With Eno I don't have to worry as much because if someone get the card number I can just delete the virtual number without replacing my entire card and the headache of changing every auto payment. It has worked for me every time I have used it. I could see where the pop up might be bothersome if Capital One isn't your primary card but I don't mind just closing when it's not needed.