[jychang]

Yeah, a lot of people are hung up on the "takes 4 days to brute force" part.

I'd be willing to guess that most phones have a passcode that's like "1234", or between the numbers 1900 and 2100. 300 tries can easily get a vast majority of 4 digit passcodes, let alone 4 days' worth of tries.

[kalleboo]

You don't have to guess, the post you're replying to showed 11% of users had 1234 as their PIN, and has a detailed analysis of common patterns, such as birth years and PIN pad patterns (2580). You should read it, it's interesting.