Originally Posted by
maball
You even get this when you try to search for flights
Yes, I get this when using Vueling's website from China, where there is a well known problem with stolen credit cards. Using VPN tends to solve this. It sounds like you were on the wrong side of "whitelisting" which is also used by both BA and Iberia. It may be that using Incognito / InPrivate mode would also work.