Recently, a bug was discovered in iOS 5.0.1 that allows anyone access to a locked devices contacts data. This is not the first time a bug has come up, as Apple usually patches problems quickly, depending on the severity. This bug, however, is more complicated and involves opening and closing the sim tray along with knowing the number of the phone you want to unlock. While the procedure may be inconvenient, the bug still posses a threat to people with high privacy levels. Anyone concerned with this issue should update to the next firmware as soon as Apple releases it.
If you would like to know how it is done check out iPhone Islam’s video showing off the bug.