Just how easy is it to open a locked PVC door with a credit card?

I've got a wooden front door but I'm thinking of getting a PVC door instead. A friend of mine told me that it's very easy for burglars to open PVC doors by using a credit card to get it open by sliding it between the door and the door frame and opening the door with the handle. I'm a bit worried about this and it's starting to put me off getting one. Is this just an urban myth or is it that easy to open a locked PVC door?