I called them today to validate my card, they are great! they ask you a bunch of questions all of which you should have been able to answer by the second grade.
Just signed up there myself today as well - I called them, because I'm at GMT+2, meaning (with my luck) they'll call at 3am. It was completely painless - they just ask you to confirm your credit card info and I was up and running in 2 minutes after I ended the call (which took just under 4 minutes).