Examples? Here are the biggies to look out for:
- Screenshots. Every time you (or your app's users) press the home key while they are running your app, the default behavior in iOS causes a screenshot to be made and stored in plain view on the device.
- Spell checker. In order for that nifty, sometimes annoying, and often funny spell checker to work, the system keeps a running cache of what you type, even if it happens to be fairly sensitive. (Some data fields, like passwords, are generally protected from this.)
- Cut-n-paste. Anything you put in the cut-n-paste buffer is readily accessible from any app. Face it, the feature wouldn't be so useful if you couldn't move data around.