If the bank pin cracker works as I think it will then it would take a longer time(average) to crack the pin than it would take for the pin to expire from the "I Don't Know" option?
As far as I know you try 3 pins, (the last one is a 10 second wait) then you log out, log in, repeat.
Is that how you're script would work Chewbaka? Also if you was going to do that I'd suggest not doing it in order from 1000-9999, but have that as the range and let it pick random numbers between there, make a check also that it doesn't repeat any.
As far as I can think the only way to do it quicker than that would be to exploit a bug, of course if such a bug did exist it would be extremely private. I've tried on a number of times to find a bug in the bank pin system, to no success
What I do right now if I don't get their pin before I take the account is
1) Try and social engineer the owner into giving the pin, if that fails...
2) Bot the account 24/7 never letting it log out, it's a simple script that never fails, If you're going to do this make sure you start right after RS updates on tuesday/wednesday, otherwise if they change the password from a safe computer and you log out due to the update you can say bye bye.
Gonna post a story and pic over @ Your Spoinkls in a second, it's to do with method 1), social engineer the pin.