Yes, I've been flagged too on my account- in the middle of a lengthy purchase at none other than Walmart, where you have to wait an hour in line in the first place.

When we moved to Denver we were a bit short on cash after shelling out so much money for first month's rent and deposit, so we used our card. The company was suspicious that someone from Iowa was spending so much money in Colorado so I couldn't check out at, and I had a shopping cart full of stuff (already rung up).

So, after standing there for 10 minutes, the manager called the credit card company, I had to verify it was me using the card with a million questions, and then, they asked me, "Would I like to update my information now?"