[habosa]

That is true. Most people use a 4-digit or 6-digit numeric password and that's what the FBI is betting on when they ask to remove the brute force restrictions.

However Apple allows something like a 35-char max with numbers and letters so in the worst case they will never crack it.

[jontas]

I don't know if it is correct but I've seen it mentioned elsewhere in this thread that the passcode they need is 4 digits.