On iOS devices, you can if you are very security conscious have the device erase all your data after somebody has tried to guess your passcode lock more then 10 times.
To enable this on your iOS device go to Settings -> General -> Passcode lock (Enter your passcode if you have one set), then at the bottom flick the switch to On for Erase Data.
This could be a good move, or if you have some people in your office who like a joke and try this on people's phone for a laugh then the setting could come back to bite you.
Erase Data
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