There is a tweet from @ fixxx3rme I find a very interesting article published by the developer Daniel Amitay on his personal blog.
Daniel created a security application called Big Brother Camera Security that allows take pictures when a person accesses the iPhone without permission.
You can see a video of its operation on YouTube.
As well, the application has a lock screen similar to that of the iPhone and although the user can configure the password they want, surely many will use the same ones in both locking systems.
Daniel saved anonymously on his servers passwords used in the application, so he was able to collect the following data:
Of 204,508 passwords, the most common is the classic 1234, followed by 4 repeating numbers and online codes like 2580.
Currently the application was removed from the App Store, curiously this happened one day after Daniel published the statistical data on his blog. Apple considered that the privacy of users was not being respected when saving these passwords and to avoid claims, it opted for the easiest way.
Daniel wrote a note about it clarifying what happened and explaining that the only data he stored was the password used in the application (which is not necessarily the same as the iPhone) and with that he had no way of identifying users or devices.
And what password do you have on your mobile? I hope it's not one of those 10.
See also: Attacks on VoIP infrastructures (talk by @ fixxx3r)