I wanted to log on to my account on my bank's website. The account is protected by a number of security checks. The first one is what really amounts to a username, a confidential one. It's an 8-digit numeric passcode (given to me by the bank), after entering which I need also to enter some personal data and a password. Today, I was notified by the system that my passcode was locked out and that I had to contact the bank by phone. I did, and I was informed, after giving a fair amount of personal data to the person on the phone in order to verify my identity, that my account was now all good and I could log on. They also told me that was probably because someone used my passcode by mistake and, being unable to enter the correct information later on, locked my passcode out. I'm quite confident that that was indeed the case -- it seems rather plausible, though my first reaction was, "Someone just tried to steal my money!"
If that's what happened, it was an inconvenience for all parties involved: the person who was mistaken about their passcode was not, obviously, informed that they were entering a wrong passcode, and they wasted their time trying to enter the correct information later on; the bank had to use their human resources on helping me out; I had to waste my time and money on calling the bank at 00:05 AM on a Monday.
Is anything being done by banks or other entities in order to prevent such situations? What is being done? It's them who provide the codes, and I see no reason not to make them dissimilar among the users. I've not tried to do any calculating, but it doesn't seem very complicated to make sure certain common mistakes are not going to happen.
EDIT: Thank you for all the answers given so far. The answers stress the fact that the inconvenience was minor and I should be happy that was all that happened. I'm certainly not unhappy my money didn't get stolen. :) However, could you please address the question of dissimilarity? Is there a good reason not to make sure the randomly generated passcodes are immune to transpositions of adjacent digits for example?