However, while undeniably stupid, hopefully they have rate limiting in place so guessing the PIN would not be feasible even if you know the day the credit freeze was put into place.
pretty hacky implementation but oh well
There's an option to pick your own password during the previous step but having an automated one is the default option, so a lot of people miss it.
Your chance of being wrong in all 1000 guesses, assuming you guess randomly (not ensuring you never make the same guess twice) is (1-1/(60* 24))^1000
That's about .5
This is based on the assumption that you are guessing for a different person each time, so you can't increase your odds by eliminating any guesses you've already made. If you're guessing for the same person every time, you just need to guess half the possibilities. You can confirm this by realizing:
Your chance of being wrong in a guess is 1-1/(60* 24-x) where x is the number of guesses you have already made.
The product of 1-1/(60* 24-x) from x=0 to x=60* 24/2-1 is .5
Edit: hackernews formatting is weird