I understand different places have differing levels of "complexity" requirements for passwords, by why would there ever be a limit on the characters you can use?
One site might want 8 characters, with one number and one uppercase, and one special character, but they only allow "certain" special characters!
Some sites are ok with dashes, others, underscores... WHO CARES!
Oh, and don't get me started on credit card input "please enter just the number, no spaces or dashes" - Well, if you don't want the spaces and dashes in the user input, JUST FUCKING REMOVE them, and say "thank you" to the customer, who used to always be right, but now is apparently just a schmuck.
Was that too harsh?