Um....



...crap... Now I'm off to look at my credit card activity.



I'm guessing this is atypical - in fact, the credit card that I use for WN bookings has a hypersensitive fraud warning system in place. They've called me shortly after booking a series of normal bookings, so I think they'd twig to two identical ones, same flight, same passenger name, etc. (They somehow get flight data because they actually display it in my activity details.)