It goes farther.
When I recently changed to postimage for my photo hosting, they assigned a 12 character password. It contains a combination of numbers and letters, including both the number ZERO and the letter O multiple times in the password. There is enough of them that I still cannot put the password in myself correctly, not knowing which are a letter or a number. I have to copy and paste the password to get it entered correctly.
This is not the password, but just a similar example...
05X02O7QOOo1. Entering the characters from my keyboard, I can see a difference between zero and O. When they sent the password to me, zero's and O's are identical.
Very recently, I was told that some states will not use the letter O on a license plate because of this confusion. I remember in the Army, on any official form, we were required to put a slash through a zero, to denote it as a number and not a letter.
My vehicle VIN's have combinations of zero's and O's with no visible difference. When I talk to the insurance company on the phone and I read them the number, I always say zero or O, I can't tell, when I come to this character.