Any password is safe enough if the stupid log-in system doesn't allow unlimited attempts to guess the password. Seriously, even something as simple as 123456789 might not be guessed if the person starts at 12345, and gets cut off after three guesses. Throw a random letter or other character in there anywhere and it will NEVER be guessed on a truly secure system.
However, if your login system lets anyone guess passwords repeatedly with no count limit or mandatory wait period, then any password will be guessed, even if its IOdfdf___23123__!@dffd_34232.
Seriously, 3 tries and it locks the account for 5 minutes. 3 more an its 30 minutes, etc.. etc..
My company pisses me off cause it makes us change passwords every 3 months. Seriously, 3 months, did they do a study and figured after 3 months some hacker is getting close to guessing the password? Password security is a joke because people rely on the users to protect themselves.
I don't recall 4-digit PIN numbers for ATM cards being a major security risk. You know why? After too many failed attempts, the machine TAKES THE FREAKING CARD and the bank locks-out access to the account, no more guesses for mister criminal.