Apple provides more security for the users and especially for the iPhone users. Apple Screen unlock provides security for the users incase of misuse of the phone, the data will be wiped off and there are much more security. Recently Researchers from MDSec used an IP Box, a device that is mostly used in phone repair market to unlock the apple iOS screen.
The PIN entry over the USB and the combination of PIN in sequential bruteforce unlock the screen and the beauty of it works with the enabled settings of erase data after 10 attempts. IP box has the capability to bypass the settings and provides the result on switching on and off of the power resource at certain interval. The following video describes the process of apple phone screen unlock using IP Box by brute force attack.
They tested this will Apple iOS running 8.1