One of the cool unsung new features of iOS 6 is the way it doesn’t ask you for a password every single time you go to make an app purchase. Remember those days? Ugh.
The downside of this convenience is that anyone who uses your iOS device within about 15 minutes of you having entered the password–like to buy that free game app for your kid, you know, the one with the in-app purchases–they will be able to purchase other apps or (gasp!) complete in-app purchases without entering the password. No, Apple, I really don’t want $100 worth of Smurf Berries.
Short of turning off in-app purchases–which, really, you should if you have children using your iOS device often–there’s another way to protect yourself from this kind of snafu.